I installed Vista beta Service Pack 1 tonight and have been playing with it for a bit. Here is a quick run-down based on about an hour or two of usage of things that were on my "hoping for" list:

• Installation of the beta SP 1 took about 2 hours, but I didn't experience a single crash.
• Shutting down and returning from stand-by seems to be a better experience at this point. I can shutdown, restart, and resume from stand-by with no blackscreen issues ( at least not at this point ) It is not getting stuck at a never-ending Shutting Down screen after selecting Shut Down or Restart. That is a major big deal for me, and I'm glad to see that experience greatly improved.
• The disoriented tablet screen is still a bug: shutdown in portrait mode, restart in laptop mode, screen still displays in portrait at startup. I was secretly hoping this problem would be fixed.
• Performance does not seem to be any better or worse than before SP 1. The memory footprint about the same: about 900 mb after startup. Start up is still slow on my 2710p: 5 minutes from power up to all programs loaded up. SP 1 has not done anything to improve that or make it worse.
• I've run Office 2007 and stuff - no problems, nothing broken.

I'm looking forward to trying out the external monitor fixes that Brandon LeBlanc mentioned.

I'll be doing more testing over the coming weeks and submitting that feedback to Microsoft.l