Another problem just popped up here, post SP3 and post hotfix.
It seems that calendar entries that are imported into Outlook by the user are not synced to the Blackberry.
Wirelress sync is on (manually entered appointments do sync correctly), and it looks like the changes are queued on the BES, but not send to the Blackberry.
On the Blackberry go to Calendar, Options, and switch wireless synchronisation off, then on again.
After that, the BES immediately sends out the queued updates.