I've got an RC1 server going, and we're playing with the shared email folders.
When a user2 is connected to user1's shared folder, user2 must reload the client to see updates, such as adding or removing subfolders, or even if user1 deletes the shared folder in question. Even if user2, with manager access, creates a subfolder this happens.
When I refresh user2's browser page, or log out/back in.. the folder information is updated, or when user1's shared folder itself is deleted, user2's will be marked with strikeout. I was not able to have this refresh any other way.
I hope that's clear enough. I didn't see any bugs specific to this, but it may also be tracked by another bug.
This was using the rich client in FF2/linux.