From full article here: http://www.comicbookresources.com/?p...ticle&id=38129Captain America returns to the Ultimate Universe this summer for a crossover event between "Ultimate Comics Spider-Man," "Ultimate Comics X-Men" and "Ultimate Comics The Ultimates." Again, Singh promised national attention for the story akin to the death of Johnny Storm based on a key decision a character makes within the course of the crossover. Overall, Singh called Marvel's plans for 2012 historic on many fronts with the final tease being a major shake up in the wake of "Avengers Vs. X-Men."
My prediction is that character who makes a key decision will be Kitty Pryde! (wait, did I say my prediction or my wishful thinking )
If you think about it, if it's a summer event then it will be starting around the time Brian takes over X-Men and Sam fly’s solo on The Ultimates, and if it was just about the return of Captain America, then that could be handled perfectly well within that book alone.
If it's a crossover it stands to reason that the X-Men will be involved quite heavily and with what we know of the upcoming storylines, it does make sense that Kitty could be the character they are alluding to?