Adam Ozimek says that despite what you may have heard, Fitch has not affirmed its AAA; they're still reviewing the matter. (Moodys is also apparently threatening to downgrade us by 2013 if matters don't improve. Ozimek identifies what I think is the key question:
So despite media reports like those above, Fitch has not "formally reaffirmed" the AAA rating, and a downgrade appears to be on the table for their upcoming review.
One thing to consider is that an S&P downgrade could make a Fitch downgrade more or less likely.
But which is it? I can see it two ways: