Doesn't look like it has been released yet. You can probably track here:
https://www.myciscocommunity.com/message/33149?tstart=0
and, according to Cisco when the Exchange 2010 is supported, the following document will be updated.
http://www.cisco.com/en/US/docs/voice_ip_comm/unity/7x/requirements/7xcusysreq.html#wp472166
I checked the voice downloads site and I didn't see any updates related to Exch 2010.
HTH.
Regards,
Bill