Today, we enabled voice within our OCS2007RTM deployment. So we connect our voicegateway AudioCodes MP114 FXS/FXO to 2 analog lines and there we go. We use a per user defined policy and one location profile loaded in OCS. The default route is .*. So everything is a very nice experience especially in a working environment.
Here some printscreens of voice integrated in OCS2007RTM:
Incoming call:
Accept call:

Make a call:

Sometimes OCS is very difficult to troubleshoot. Make sure you use the OCSlogger.exe and snooper.exe tool to drill down your OCS logging and tracefiles. Excellent tools to work with!