I'm very happy running both LR and CS3 on Vista. Now that the Release Candidate for SP1 is publicly available, I can say that SP1 will deliver improvements in several areas including:
File Copy performance, both Internal and Network. This made a *huge* difference on my laptop, my desktop with SCSCI disks not as noticeable, network performance however showed great improvement across the board - apparently Vista, which is based on Server 2003 code, not XP, inherited the user disk quota and throttling mechanisms, which are usefull for a shared resource in a networked environment, however, not optimal for an individual user tossing 10GB folders about . . .
UAC Prompts no longer nail the currently loaded Display Profile. I hope I don't get in trouble on this one . . . my Eye-One display profiles currently survive full UAC prompts without having to reload the profile, or re-login. This with latest Eye-One Match bits: 3.6.2
Energy management, including fixes to hibernate/standbye wake-ups.
Program Compatibility, including PS plugins - I'm no longer getting UAC prompts
All that said: My experience is based on VISTA SP1 RC which is a BETA and WILL CHANGE before final release, supposedly early 2008. I DO NOT recommend you install this publicly available beta on a production machine.
hth - John