Alright,here's my updated "Mass Effect Trilogy Remastered Edition" ultimate wish list:
______________________________________________________________________________________________
Mass Effect 1
Major changes:
HD textures (for everything) - 2K Standard for PC with an optional 4K included in the files if the user's PC can handle it. For consoles,whichever texture resolution is the maximum limit. The textures are completely optional,so you may still use the old ones if you wish.
The fan-made "Mass Effect HD Retexture/Remake" is also included in the files if the player wants to use them instead.
New Assets - Brand new,HD assets (for interiors,exteriors,objects,buildings,etc.) made specifically for ME1 to fit in with the art style of ME3/ME2.
Improved lightning,shadows and shader
All of the DLC and promotional/pre-order items - The DLC is also fully integrated into the story.
More weapon and armor variety as well as improved design/art of the existing armor/weapons - Shepard's iconic N7 armor from ME2/3 is also used as the default armor in ME1. Next to that,all existing weapons and armor get a sort of redesign so that they have more detail while keeping the spirit of the original armors.
Better Mako controls (even though imo they were always fine)
Mini-games On/Off - The option to disable all of the mini-games and replace them with a ME3's auto-success.
Improved AI
All remaining bugs fixed - There aren't many left though,but there are still some minor ones.
Sync the story with ME2 and 3 - Since there were a few major retcons in ME2/3 (the all-human council,the battle with sovereign,etc.) and some smaller ones,those story elements are now rewritten so that they are no longer incompatible.
Mass Effect 2
Major changes:
HD textures (for everything) - 2K as a standard,with the optional 4K textures included in the files. As always,the textures are optional.
Improved lighting,shadows and shader.
An additional way to get minerals- Next to the tedious mining,there should be some new way to gain minerals. Or maybe just reduce the amount of minerals required for the upgrades?
Mini Games On/Off - The option to disable the mini-games and replace them with ME3's auto success.
Fix all the minor plot inconsistencies - That might have been overlooked or retconed in ME3.
All of the DLC and promotional/pre-order items - Overlord,LotSB,Kasumi/Zaeed and Arrival are all included in the story and "organically" integrated into the plot. Arrival and LotSB are now tied into the story with cutscenes rather then emails and play after the Suicide Mission,while Overlord happens whenever the developers think is best.
Minor changes:
- Make all recruitments available from the very beginning like it was originally intended.
Mass Effect 3
Major changes:
HD textures (for everything),shadow and lighting improvements - 2K texture resolution as a standard,4K as optional.
All DLC and all promotional/pre-order items that were ever released
DLC story integration - That means that for example Omega and Leviathan no longer open up after Mars. From Ashes,Leviathan,Omega and Citadel are now integrated into the main plot (cutscenes,Hackett's reports,etc.) and are a part of the story progression just like Tuchanka,Thessia or Rannoch,like they were there from the beginning.
All DLC names are also renamed to "Priority:" (i.e. "Priority:Omega,or "Priority: Shore Leave") instead of "Omega:" or "Leviathan:".
Recommended setup:
From Ashes - Opens up right after Mars. The mission is acquired by talking to Hackett who informs you about the Prothean dig site rather then through an email.
Omega - Aria now mentions she will be retaking Omega and that she will need your help when you first meet her on the Citadel. After enlisting the aid of the Blue Suns,Eclipse and Blood Pack mercs Shepard can mention he will be retaking Omega when talking to Hackett over the vid-com,to which Hackett offers his opinion.
After Omega,Shepard may tell Hackett the station is back under Aria's control which Hackett will confirm,saying that large amounts of Eezo are being transferred to the Alliance and thanks Shepard for liberating the station.
The Omega Nebula system is also available on the Galaxy Map throughout the entire game. The description changes upon completing the DLC,recognizing that the station has been liberated from Cerbeus.
Leviathan - Leviathan now starts after Rannoch and before Thessia. Hackett now tells you about Bryson's research through vidcom and the DLC plays out.
However,just before the final mission (Leviathan: Despiona),the Asari Councilor will contact you over the vidcom,schedule a meeting and Thessia will open up like in the vanilla game.
This gives the player a choice of either completing Leviathan first,and learning about the Crucible and the Catalyst from the Leviathans,or doing Thessia first and learning about the Crucible from the Prothean VI.
The dialogue on Thessia changes depending on which whether the player finishes Leviathan or Thessia first (unlike in the vanilla game).
Citadel - The DLC starts and plays out after Sanctuary.
Like in the vanilla game Hackett orders the Normandy into dry dock (through vidcom after Sanctuary and through an email),but this time,while the fleets are preparing to strike against Cerberus and retake Earth. The "She's seen a lot of battle and little TLC" reason is still present,but now Hackett tells Shepard he/she has earned a break and deserves some shore leave while the fleets prepare.
Of course,Cronos Station only becomes available after the party is over and the player returns to the Normandy. 
Fix and improve the Journal
Fix all bugs and glitches - Especially in DLC like Omega.
War Asset Strength Rebalance - A lot of War Asset values make absolutely no sense. A lot of them are either overpowered or underpowered,and some "bad consequences" of our previous actions in the trilogy are completely minor and don't have a big enough effect (e.g. The Alliance fleets losing ships in ME1).
New War Assets,emails and N7 Missions - Mass Effect 3 had some pretty interesting missions that were unfortunately boiled down to mere planet scanning.
Why not actually go to Dekuuna and escort the Elcor civilians myself,seeing the Reaper devastation firsthand and maybe even seeing some Elcor Warriors in action?
Or why not free Barla Von's mercenaries myself instead of magically saving them by scanning the planet?
Regarding War Assets and emails: New War Assets are very easy to create even by the modding community,and since a bunch of new War Assets were added in all DLC with the exception of From Ashes and maybe Citadel,I don't see why we couldn't get some more in the Remastered Edition?
Basically,something similar to this mod. Maybe even include the mod itself?
Priority:Earth Remake
And I don't mean the Catalyst. I mean the actual "battle".
Here's a link to one of my previous posts explaining in detail the potential changes and new content for the Remastered Edition.
To be honest I'd be pretty disappointed if the Remastered Edition didn't include any changes or new content for P:E,as everything listed there can fit into the budget. A new soundtrack,map,some story contradiction fixes,and a couple of new cutscenes are nothing special.
Of course,a complete remake from scratch with a Tuchanka-like treatment,a new,longer and more interesting story,and new cinematics/cutscenes reflecting our fleets and final forces would be even better lol,but that would be too much for a Remastered Edition (doesn't mean you don't have to try,of course). 
General changes to the trilogy
Major changes:
Character Model Sync - All characters (such as Anderson ,Ashley or Liara) whose face has been changed in ME3 should have their face changed in ME1/2 to reflect the new models.
Improved and expanded character creator - It doesn't have to be like DA:I,but an improved character creator is a must for the Remastered Edition.
All three games tied together into a "single adventure" - This is something Aaron mentioned. It would be nice if all three games would be unified into a "single adventure" without having to launch each game separately and import the save files.
Class and face changes would be handled as usual.
ME3 Multiplayer for Next-Gen consoles - It would also be nice if we could carry over progress from current-gen or from our PC into the next-gen versions.
Minor changes:
Femshep's default ME3 face is now the default face in ME1/2 as well.
Quarian evirosuits in ME2 have been updated to reflect the new models from ME3.
_______________________________________________________________________________________________________
That's pretty much it.
Thoughts?