There's no way Santorum or Gingrich will win the majority of delegates left, let alone catch up. But for Romney to win the majority of delegates, that's still very much a toss-up. Remember he's won 54.9% of the delegates so far, now he needs to win the remaining 49.7%, most of which are in states and counties that are not favorable to him. It's close.
agreed.
I'm still hoping for a brokered convention, so I may be optimistically biased in favor of your analysis.
By the way, when I link to RCP, I see that they have Willard down for 560 delegates.