I have questions for what seems to be a popular problem...exchange coexistence with exchange 2010, 2003 for free/busy and Outlook 2007/2010 clients.
* Exchange 2010 SP1 and Exchange 2003
* Mailbox on 2010 with Outlook 2003 can see free/busy - Outlook 2007/2010 cannot see free/busy for any user with a legacy mailbox on Exch 2003 (however they can see free/busy for other users on Exchange 2010).
* OWA on Exchange 2010 - free/busy for legacy mailboxes on Exch 2003 CAN be seen
I've seen many posts and at this point I'm not sure what the correct expected behavior is for Outlook 2007/2010. Is it expected behavior for Outlook 2007 to not see legacy free/busy (without doing the obnoxious registry hack forcing legacy mode (until all mailboxes come over to 2010))? If after Exch 2010 SP1 the availability services IS supposed to carry legacy free/busy to Outlook clients please let me know. Given that OWA on Exchange 2010 can see legacy free/busy, I think the free/busy replication from 2003 is working....