Lots of subtle changes. Nothing earth-shattering and in-your-face at first glance.
Launchpad is a nice way to view your app list, but I don't quite get it's existence in the Dock. That said, I would love to be able to have folders in my Dock, since on my main Macs, I have about 48 apps in the Dock.
Using multitouch gestures on the trackpad to swap between applications and workspacesis very awesome, though.
Can't play with AirDrop yet, as I don't have multiple Macs that I can put Lion on just yet. I wonder if it's going to be a DropBox replacement.