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).
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There's tons more cool shit. Watch the video.