This is looking pretty good, especially considering how absolutely terrible Apple has increasingly managed to make iChat/Messages recently.
A huge feature for me and my team would be the ability to use encryption, specifically private/public key pairs. If all messages could be encrypted on the client, then your servers would never store plaintext, and then I think I wouldn't even mind whether you hosted it or not.
I would make that trade if necessary. Alternatively, the search could happen client side (which I understand is more difficult, which is why I'm willing to have no search)
A huge feature for me and my team would be the ability to use encryption, specifically private/public key pairs. If all messages could be encrypted on the client, then your servers would never store plaintext, and then I think I wouldn't even mind whether you hosted it or not.