I installed Leopard on my 24" iMac and boy is it nice! I haven't configured time machine yet because I don't have a backup hard drive, but I recently got the new Xcode developing tools and DashCode, which lets you create widgets for web and for Dashboard on the Mac. XCode has a big library with all types of code that you can search. It's really neat.
If you wanna see any pictures of the wait at the apple store click
here
I was second in line, and waited for three hours. But I got leopard and a free cool tshirt.