This is an initial summary of the replies from the threads at StudioSysadmins and sysadminbash regarding windows 7 Deployment.

Pros:
*) Super zippy compared to Vista. --Trace Bloomer
*) No blue screens, no crashes on either of the three systems I help set up, that I am aware of. --Eric Jordan
*) The general consensus is that it has better performance and stability, specifically in regards to the nVidia Graphics drivers compared to vista. --Trace Bloomer
*) File copy operations are much faster. (100MB/S from a standard workstation to first gen Isilon system) --Saker Klippsten
*) Ditches USB and FireWire drives "like that" when your unmount them. --Eric Jordan

Cons:
*) Problems authenticating against an OSX Server 10.5.7  OD --Daniel Roizman
*) nvidia graphics driver tends to have issues managing memory and we frequently blue screen when using (Maya, Zbrush and Photoshop) --Daniel Roizman
*) Maya 2010 had a few issues. --Wes Anderson
*) some issues reported but resolved relating to mocap software --Gary Giambalvo
*) still at Service Pack 0, which I've avoided with all of the Win releases. --Eric Jordan

Advice:
* Go with Widows 7 Professional, it offers Volume Licensing using one serial. --Trace Bloomer, David Krause
* Create a "GodMode folder" for quick access to all the configuration panels. --David Krause, --Saker Klippsten

As more information becomes available it will be posted here.