There are some cool things coming in Leopard (Apple's newest version of OS X). I recommend you take the time to watch the Keynote Address. As usual, there's a bunch of eye candy/fluff in Leopard, and it'll be interesting to see if they fix any of the numerous bugs that have been around since day one.
So, they've added a bunch of wizzy stuff in Mail that I could care less about. The ToDo thing might be cool; we'll see. I really want to know if they fixed the URL-splitting bug. My insider friend tells me that bug is fixed in Leopard, but it wasn't mentioned in the keynote (had it been, it would've received the loudest applause).
There's tons more cool shit. Watch the video.