A couple of kinks in SL, but the most frustrating one for me was that I was not able to do a screen-shot via CTRL + Shift + Cmd + 4 and then paste the screenshot into Mail or any other application. Strangely enough this worked fine before the upgrade and after upgrading to SL, I was only able to paste into a few select applications.
The fix is quite easy, you just need to delete one preference file and then log-out/log-in:
Delete the plist-file from /User/Library/Preferences/com.apple.screencapture.plist