User blog comment:LilyheartsLightning/Citadel and Reckoning DLC announced/@comment-2130363-20130223225537/@comment-5267262-20130224115320

I would assume that when you do this will heavily change who you can take. In other words I think squadmates will become available/unavailable as time passes. (spoilers but tbh if you are reading this you already know of them) And onbiously you need to have not killed them off in earlier games. It looks like some combinations are unfortunately going to not be possible.
 * VS needs to have come out of coma before they can be used (Possibly also needs to be after priority citadel)
 * other actual ME3 squadmates would have been recruited first.
 * Mordin needs to have not gone and blown up first.
 * Jacob has to have been taken away from his ice planet hidey hole.
 * Thane has to have not gone and died.
 * Samara must have not committed suicide (maybe she would be usable before that mission).
 * Kasumi and zaeed (if he is in this) after they turn up on the citadel.
 * Miranda, I would think anytime provided she hasn't died on horizon.
 * Wrex anytime/after tuchunka provided you never killed him.
 * Legion between priority geth dreadnought and rannoch.
 * Grunt after that rachni mission as long as he didn't die.

In other news, it looks like shepard can collect all those drinks that half the galaxy owes him/her.