Yes, this feature would be cool. Although it cannot be implemented inside the browser without ActiveX (Outlook), but it could be implemented as a separate application, which uses the existing seervices in the phone and communicates wia web-services (f.e.).
Outlook synch:
- contacts (with special tags/groups, with profile pictures, etc.)
- calendars
- notes
Syncing all photos, and so on...
At the time the biggest reason to stick with HTC is the HTC synch tool which does exactly this stuff. Also Samsung Kies has some similar functionality (not via Kies Air, but with USB conection + PC app).
Hope this helps.