Mac OS X Tiger: What is the "one more thing"?

By now we've heard about Apple's upcoming release of Mac OS X 10.4, a.k.a. Tiger. It's scheduled for the end of this month: April 29th.

And all of the features are known. Michael Gartenberg gushes about the release, saying he's "still convinced that Tiger is a big deal and it just might be the the best OS on a PC I have ever seen for productivity use".

But we've come to expect something more. Jobs always seems to have a rabbit up his sleeve. Or maybe the new OS really is that good, that installing it/using it IS the rabbit? I can tell people are looking for more info -- my rumours post on 10.4 is getting lots of traffic.

Here's my related but somewhat random rumour: Scoble has been talking Apple a lot lately. Jobs has convinced him to come to Apple to do tablet evangelism (that's the one more thing, and here's my Mac tablet spec) and kickstart Apple's entry into the blogosphere.

What do you think? What are you most looking forward to in Tiger?