Since ADR isn't a choice, I went with Morrison. Although, I think he will need to be traded to Smackdown first. I don't see Morrison beating out guys like Orton, Cena, The Miz etc for a title run quite yet, but WWE should cash in on Morrison while he is still very over, especially since things have cooled for him since his fued with Sheamus. Smackdown needs a young top face, and a Morrison vs. ADR fued over the title would be pretty great for a post-Wrestlemania program. If Miz retains at mania, I could also see Morison taking the belt off him possibly.
As for the others:
Kofi Kingston: I just posted my thoughts on him on another thread, so in summary, while I enjoy his work, and he could get a late push like Jeff Hardy or RVD, but he is just too bland right now to take him as a serious title threat.
Drew McIntyre: I thoroughly enjoy Drew's work, and think he is definitely a future contender, but he is currently lost in the shuffle on the Road to Wrestlemania, and I don't see him rebuilding steam till later in the year, possible MITB winner this year.
Christian: I have been skeptical of Christian being World Title worthy since he returned, but I think he could do alright, however, with a possible heel turn and fued with Edge, I don't see him getting the title before Morrison.
R-Truth: His time has come and gone, and while I thought it was a possibility a while back, I think he will continue to fill a midcard spot till he leaves.
Evan Bourne- I enjoy Bourne's work in the ring, but I don't think he quite fits the bill for World Champion right now. I haven't heard him cut a promo, and there is probably good reason for that. I'd say he is in the same boat as Kofi Kingston.
Wade Barrett- I think he will win a title by next year, and is my #2 pick out of the group, but I think he will carry the IC title for a good while to rebuild his credibility.
He is the total package right now, and I see him as a major player for years to come. Could also walk out of MITB with a case this year.