This is an old and rich topic, but I think one part of the problem with "conservatism's over" school is that people confuse intellectual conservatism for popular conservatism generally. They are overlapping and mutually dependent movements, to be sure, but less so than most of the disgruntled intellectual types think. If the popular political movement does something at odds with the intellectual precepts of the eggheads, someone invariably yells "aha! the movement cannot sustain such internal contradictions!"
The problem is that all serious and large political and ideological movements contain internal contradictions. Internal contradictions come with growth. Perfect internal consistency comes with contraction and insularity. Small cults are internally consistent on every point. Large movements must deal with coalitions of competing interests.
This doesn't mean such contradictions don't create problems and challenges, but if you're looking for a major coalition to fall apart, you should look less for intellectual contradictions and more for conflicts of interests between major segments of the coalition. The intellectual conflicts are interesting to intellectuals -- that's why we call them "intellectuals" -- but they don't always reflect concrete antagonisms within the movement. Frank Meyer's fusionism -- the marriage between traditional or social conservatism and anti-state or libertarian conservatism -- never really worked on paper very well. But despite this internal contradiction -- capitalism versus stability -- the conservative movement prospered because it believed such a marriage would be useful ideal even if it couldn't be attained in practice.
Those who want to find in the Schiavo case proof of a movement-splitting schism need to demonstrate that a major constituent of the conservative movement -- free marketers, for example -- can no longer abide by fighting side-by-side with pro-lifers or social-conservatives.
By the way, my pals Andrew and Justin are tossing this around over at Anchor Rising, too. (Andrew, Justin, Andrew 2)