Fresh install from 7.1.2 Unity connection DVD. Then upgraded to Unity connection 7.1.3 by downloading from CCO.
7.1.3 Unity connection release notes mention that MWI is able to send message counts to IP phones when integrated with CUCM (7.1.3) using SCCP.
I have the above setup and under user -> edit -> Message Waiting Indicator. There are no options to check a box "Send message count".
However, there is an option to send message counts under the system phone integration and I have checked that box. But the phone (7970) only displays "You have Voicemail".