I thought I’d really be pushing my luck, but it appears that the VMware Virtual Infrastructure Client (Build 119598) runs fine on the 64-bit Windows 7 beta (Build 7000). I only have the basic client and the Update Manager plugins installed, but both appear to work. I’ve done a solid 15 minutes of testing so far, so YMMV. :-)
It’s probably also worth mentioning that my test Windows 7 host is a VM in my VI 3.5 U3 cluster. Seems to work — the VM is set to Windows Server 2008, and the VMware Tools seem to work fine. I didn’t install the Shared Folders functionality. It sure is nice to take snapshots along the way as I install more software and drivers.
All of this is obviously not supported by anybody, but if you’re looking to check out the new beta you probably are used to doing your own support anyhow. Good luck!