Yes! Photoshop CS2 and Lightroom run *great* on Vista.
My current test platform is side by side install on my home server, a Dell Dual Xeon PowerEdge w/8GB Ram, normally running Windows Server 2003 SP1. Note that Vista's codebase is much closer to Windows Server 2003 than Windows XP.
There are some anomally's that I would attribute to hardware - my SCSI drive controller uses a 256MB battery backed up cache, Import's from external media in Lightroom fail, however manually bringing in images, then using import by reference in Lightroom works just fine.
I have yet to install plug-ins, but photoshop itself activated just fine. I've been told by someone at MS that the vast majority of software "activation" schemes are actually made by a handfull of 3rd party makers (we use LogicProtect) - these are all completely supported in Windows Vista by a mechanism known as "shims".
Printing is problematic, I have yet to get an HP Color Laserjet working correctly, ask your current printer maker for updated drivers. I've told Canon I will defer my printer purchase until they ship a 64bit Vista driver (I don't expect *any* answer from them until at least Jan 30th 2007