I've been running Adobe Audition 3 and the Ozone 4 VST on the 64-bit versions of Windows 7 release candidate and then the production Win 7 Pro since last Spring with no problems (fewer issues than I experienced with Vista, at any rate). You need to apply a 3.0.1 patch from Adobe for Audition to run on the x64 version. Audition only runs as a 32-bit app, but the nice thing about x64 is I can run two instances of Audition to process large 24-bit files simultaneously on a Core i7 machine with multiple SATA drives and 12Gb of RAM - I use one drive for audio files and two others for workspace. Handy when I have a lot of resampling or dithering to do.
Also installed Win 7 Home Premium x32 on my laptop and my wife's PC in November. Much better UI and home networking implementation than Vista. Only hardware/software I've had issues with is a HD-PVR TV capture device, still waiting for a Win 7 driver from Hauppauge.