Well PageRank Dead, nope, just a technical glitch. Also, nothing to do with TrustRank... Message # 359 by GoogleGuy at WebmasterWorld says:
I suspect that the toolbar pagerank will be visible again in a few hours or so--I'll ask around about it...
It's true that long holiday weekends are the best time to switch in or out different pieces of infrastructure.
no trustrank, just back to the normal display.
I talked to a few people and there was some new infrastructure that was swapping in. They expect normal toolbar pagerank display to resume in a few hours--no need for concern.
More forum discussion at Search Engine Watch and I am sure the others. I am seeing the PR values shining, DigitalPoint was right again.