24 hour rule
This assassination did not come out of the clear blue sky. This column summarizes the October attack, and as I posted above, there was another attempt the day before the successful one. And it's not like there haven't been similar attempts against Musharaff.
I'm willing to see more evidence, of course, but at this point I think there's definitely a trout in the milk.
TPM is doing a fairly reasonable job of following the story, although I know who Ackerman would like to see wearing the Black Hat.