I test sometimes native IE in Wine with the least possible changes.
With my implementation of shlwapi,SHCreateThreadRef this week, the native IE UI came up in Wine, using our shell replacement, mshtml with gecko and all that low level stuff:
http://www.myimg.de/?img=ieinwineef89e.png
The related COM interfaces for the IE Style UI are implemented in shdocvw (IWebBrowser and IInternetExplorer) and browseui (for user elements: Menu, Addressbar)
You need to copy shdocvw.dll, browseui.dll and browselc.dll to ~/.wine_drive_c/windows/system32/ and override shdocvw and browseui to native. (native browseui.dll needs browselc.dll)
It works, but it's unstable and the Menu as well as the Addressbar are absend (not registered in Wine).
register browseui.dll (or use regedit for minimal changes)
"Menu Band" CLSID: {5b4dae26-b807-11d0-9815-00c04fd91972} InProcServer32 is "%systemroot%\system32\browseui.dll" and ThreadingModel is Apartment
"Address" has CLSID {01E04581-4EEE-11D0-BFE9-00AA005B4383} InProcServer32 is "%systemroot%\system32\browseui.dll", ThreadingModel is Apartment and Implemented Categories need the subkey {00021492-0000-0000-C000-000000000046}
(IE8 has still the full IE6 style UI available)
Happy testing, and don't forget to fill bugzilla.