Here are some updates about how to make this work.
1 - After putting "userenv.dll" into the drive_c/windows/System32 directory, make sure to run winecfg in that bottle and add a dll override for it. Set it to (native, builtin). This should fix errors about the file not being found.
2 - iTunes 7 does not work yet. The installer does not run, and even if I install it manually, or run the installer in vanilla wine (in which case it works) iTunes will not launch.
3 - I have made iTunes 6.0.5 work. Use the link in the last post to get a copy and follow the directions in "Tips & Tricks" using the LATEST version of Quicktime, currently 7.1.3. It will no longer complain about the wrong version of Quicktime being installed and generally "just work." It seems faster than 4.7 also.
Hope this all helps someone!
-Matthew D'Asaro (7jp4-guy)