Like the title says, I bought Leopard and installed it on my MacBook Pro. Works like a charm. 1 thing I already like is the new stack possibility. I'm eager to see how Windows 7, as it's codenamed for the moment, will also provide this feature in 2010 when it ships.
Another thing that I really like to try out in the coming weeks is Bootcamp, or the possibility to install Windows on a Mac. The reason I want this is because my MacBook Pro has a decent 3D video card while my DELL laptop has none (so no fancy Areo for this fellow at the moment).
The installation, or better stated update, of Leopard went smoothly. I'm not sure if I'll be using Time Machine for now as it's merely a play thing at the moment for me instead of a hardcore development environment. I guess we'll see what the future will hold.