Has anyone successfully virtualized (thinapp or other) IE6 or IE7, and successfully ran it on Vista?

Yes, have done this as well as chrome and run them on vista (not 7 yet)  pm me and I can share :)

No, but I did find a fun programme called multiple ie, that let me run every version of ie from Version 2 - 7 inclusive on the same machine. Totally unsupported I am sure, but if you are doing this for fun, then check it out from here http://tredosoft.com/Multiple_IE

Two answers: 1. Virtualizing the entire IE application with thinapp is a strange support blackhole right now. 2. the good news is that under multiple scenarios, virtualizing IE ver 6, 7, or 8 can be successful. UAC on vista has been an issue in the past but only on certain versions of vista. I have been successful with it on vista enterprise 32bit but not 64 bit and a few of the other versions. Here is the tricky part each Vista version appears to treat IE differently. I know, good stuff.

Ray