A complete rewrite of the endings I guess is what people wanted.
Even though I have not been able to see them myself yet, as I am playing through the entire game again, from what I have seen it seems that it has satisfied a great many people that where complaining before. As for everyone else still complaining, they will probably never be happy no matter what Bioware decides to do.
What people wanted out of the ending?! I dunno; maybe one that was less lame? One that had no Citadel Child story, or one. Or one that didn't let you return to the Normandy with still missions to run, perhaps? Many things.
But all of it is probably a bit off-topic here. So, I'll suffice to say people likely wanted the new 'fixed' ending to be really rewritten; as in an entirely different, new ending. Which we didn't get... at all.
Fact is we did not need a new ending and the endings in my opinion were fine the way they were. I didn't feel as if there were any plotholes to be filled as some people have said.