The Chinese are reportedly prepared to use EMP weapons against Taiwan or against our forces trying to intervene to protect Taiwan.
Of course, the problem is that rather than being grateful that China didn't slam a HE warhead into one of our carriers, we might be doubly mad at being nuked--even if only a little.
UPDATE: Strategypage doesn't think that China has managed to develop the long-sought non-nuke EMP weapon. Which is what I assumed and why I think that using a nuke to EMP our carriers is unlikely.