Sitrol wrote...
I would be really happy if everyone from ME1 and ME2 were in ME3,considering that they're not dead.
But the two characters I really want are: Wrex and Garrus.Why?Because they were my squad in ME1.They kick ass...they're by far my favourite characters.And IF Wrex succeeds in strengthening the Krogan race as a whole...well that's a whole Korgan army + Shepard and his squad against the Reapers.And as the others have said:Garrus has really no reason to leave Shepard...
If I was thinking in terms of the story, Wrex will be needed to lead that Krogan army in ME3, thus be a very important character in the plot, but too busy to be in the squad. Unless there was an action level where you join up with his army, only to split off with him as a part of an attack plan or something, but he's only in the squad for that level. That would work out pretty cool if written right!
The same for Legion, he'd be a good representative for the Geth army if they join in the fight against the reapers (which I think is logical with or without him based on what he said about the Geth's mindset in ME2). Again, to busy to be part of the squad, but important.
They could do this with a LOT of the existing characters that don't make the squad(assuming they lived):
Zaeed could take over the Blue Suns again and have them participate, with Jack's disposition she could be his right hand "man".
Miranda &/or Jacob could direct whatever forces Cerberus adds to the mix.
Wrex & Grunt could fight with the Krogan Army.
Ashley/Kaiden in the army forces.
Thane (if he didn't die from illness) could gather up any other assassin's he know for a special task
Kasumi could steal TIM's ashtray.
Mordin could create a cure for the 'phage as incentive for the Krogans to fight.
Samara could use her role to encourage the Asari to prepare sooner versus later for the upcoming conflict.
Any characters that don't have a good story reason to not be on the crew could potentially stay: Tali, Garrus, Kasumi, etc. Leaving a bit of space for some new characters to be recruited, if that was the plan.
This is just some 'musings', there is so much to the ME universe that can support LOTS of great ideas, Bioware will be able to think of some great ideas to explain who's on or off the crew.