I'll install it on my PB17 as soon as humanly possible. I'm looking forward to it. Surprisingly, none of the major new features are amazingly appealing to me:
Spotlight: Quicksilver's ability to call up applications, and iTunes tracks, just might win over Spotlight's ability to look inside files.
Dashboard: Konfabulator, Dashboard... it's all the same... Might be nice not to have so many widgets taking up 5 megs a piece of vram.
Safari RSS: As long as it doesn't pause or beachball when rendering a large page or forum chatthread. RSS? Ehh... Firefox has it - not sure i'd use it much.
Mail: Will it use up gigabytes of virtual memory, if left open all night, asking for a password?
iChat AV: No one I know has any "V", and we rarely chat "A". But, i'd love to use it more, particularly with that iChat AV girl.
Automator: The things I need to automate are surely more complicated than what Automator will come with. Could be useful for a lot of people though.
VoiceOver: Is it significantly better than on the Quadra 800 AV, or are we still at "Computer, what time is it? Computer. What. Time. Is. It."
Parental Controls: I don't need to control my parents. They're pretty autonomous these days.
.Mac Sync: I don't have .Mac.
QT7: I'm very curious to watch this codec in action, but I suspect it won't do much for all my past volumes of video.