I could list 20 weapons I wouldn't mind using again... but ... I am kind of looking forward to seeing something new.
Let's not forget that Andromeda has other standards than the Milky Way, we won't find any ammo there. We'll either have to switch to new weapons or adapt ours to accept the local equivalent of thermal packs.
I'd hope they dropped the stupid "ammo" again (damned the Codex explained why you don't have to reload in ME1 damned!)...I'd rather go back to ME1-style guns (maybe with the addition of having an emergency heatsink you can cycle in if the main one is overheated or something)
On the other hand: I'd love to see some "real" laser or plasma weapons! (if there's enough time and no more reaper/prothean tech to pilfer people would have to develop their own stuff, wouldn't they?
greetings LAX
ps: On a side note, I hope to see all of the usual races again
(I hope they give us more than the 7 squadmates they are talking about ATM (in that leaked survey) because with so few, I am sure that most will be human - again (sorry, but I'd love to be the only (or one of only a few humans) human on the team...or even not to be human myself!))