I also want to register my concern about mail enabled public folder. We use them, and as a Gold Partner we have advised our clients to use them as they simplify management of info@domain.com mailboxes.
Another common use for our organization and our customers is centralizing external contacts into a public folder. This works extremely well, as that contact folder can be setup as an Outlook Address Book. Although I understand that contact folders can be handled in WSS v3, what about making that contact folder in WSS v3 an Outlook Address Book.
If you can provide a simple migration roadmap for these two issues, you will make adoption of Outook 2007 and E12 that much easier for many organizations!