I have had those thoughts as well. I believe however that a COMPLETE synchronisation module that supports ALL features of office and outlook would be a giant project that I doubt anyone would undertake. However, there are a few features that maybe are more feasible:
1. a small project module (supporting task collaboration, task assignments). This is a good alternative to using Outlook's built in utilities for delegating tasks and follow-up procedures.
2. an email /message module which preferably works with MS outlook so that there can be synchronisation between "inbox" and "sent" email.
3. a more flexible forum module that allow user to:
-ban ip
-subscribe to threads
-notification of new replies
-provide stats per user (total number of messages, date of last message) -if you click on a user's name you'll see his account, stats, and all written messages.
All this is something I want to start working on, but right now my ideas are bigger than my skills so it will take (a very) long time if I have to do all by myself. If anyone has something like this working feel free to share your ideas! =)
Mikael: the notification features your describing can be done with the notification system in 3.1.
Subscribe to threads -> that's the "Keep me updated" button you see in the default 3.1 templates ).
Notification of new replies -> this can be done with the new subscription datatype. This datatype will give you a checkbox, if you tick of this checkbox on publishing a notification rule is created so you will get e-mail about updates.