The nuclear option bothers me a bit simply because as I understand it they are dealing with a massive high pressure reservoir (call it a containment vessel). As wildman800 alluded, a nuc' could possibly solve one problem and create others. As Blast indicated, a nuc might work and then again, it might not. If it doesn't work, the problem is way worse.

Everyone (including BP) is in a hurry to fix this thing, but they really need to do it right and avoid making knee-jerk decisions that could make the problem worse than it is.