Full Screen - Great! Now the green button has a real use that is easy to understand.

A lot of apps will make great use of it.
Launch Pad - Great! Now I don't have to open Finder and scroll through a huge list of apps to find that one app I rarely have to use and don't put in my dock. I do hope they change the way folders look.
Mac App Store - Fantastic! I central place to get applications is something that computers have been needing for a long time. Now I don't have to Google them to try and find the official Website, it's down-right stupid simple to download and install, updates are just as easy, and hopefully they take on the same prices that the iPhone App Store gets.
Mission Control - Great! Just yesterday I was using Expose with a PDF with huge screenshots of a Website with instructions, and it was difficult to tell which window was Safari and which was Preview. Now they have the app icon floating above them, so that solves that problem.
Hooray Lion! I can't wait to see what else Apple brings to it. *crosses fingers for tabbed Finder*