The other demands did not seem credible. Hopefully, he is not dead, however.
The whole thing seemed confused and almost unplanned, like a crime of opportunity with different people leaping up to claim to be the "spokesman" for the kidnappers. If Daniel Pearl is dead, I suspect he was probably killed shortly after they got him; certainly, they didn't provide anything that might indicate he was really alive (the photo of a man with his head down doesn't count)
I hope we find somebody to really blast on this one. Killing journalists is a bad precedent; no matter how sketchy (or even biased, in some cases, not Pearl's) a report is, at least it provides us with more information than we would have had without it. But of course, truth is the enemy of Islam...