[keg in kc]

Another IGN read, this time on decisions from ME1 and 2 impacting 3: http://xbox360.ign.com/articles/117/1172194p1.html

It won't be easy. This is full blown galactic war and to many, the battle appears hopeless. How can any army possibly defeat the Reapers? Forget about earning the trust of individual allies -- you must unite warring factions to one purpose. Returning to Earth with anything less than a galactic armada would mean failure. In Mass Effect 2, you helped Jack deal with her past and tracked down Samara's daughter for a family reunion. Here, the stakes are higher and the importance of each mission is going to be greater.

One example of these unifying missions comes about halfway through Mass Effect 3. Shepard and crew have journeyed to the Salarian homeworld, Sur'Kesh, to rescue a Krogan princess. Yes, she's crazy hot. The princess in question is the key to uniting a divided Krogan homeworld. Mordin Solus is assisting (it is his home planet after all), and naturally the Krogan clan leader Wrex Urdnot has quite an interest in the princess.

But wait, is that team even possible in your version of Mass Effect 3? This is where the branching paths of the first two games begin to really affect the final battle against the Reapers. What if you killed Wrex in the first game? What if Mordin died at the end of Mass Effect 2? What if you gave thumbs up to the Genophage? It's unclear how these choices affect the missions -- maybe losing Mordin just means another character is there in his place -- but in some cases the differences should be significant.

Mass Effect 3 Executive Producer Casey Hudson says that "all things contribute to the war effort." Meaning every major decision from the first two games has an impact. The relationships you've built, and those you need to build going forward, matter.