The only mention of some level of support for TAPI 3.0 is the following "The Cisco TSP is written as a TAPI 2.1 provider; however, in Windows 2000 and higher, Phone Dialer uses the TAPI 3.0 API layer. While TAPI 3.0 applications are not officially supported by the Cisco TSP, TAPI 3.0 versions of Phone Dialer should still work as described below for troubleshooting purposes."
http://www.cisco.com/en/US/products/sw/voicesw/ps556/prod_troubleshooting_guide_chapter09186a00801d3ab0.html
HTH
Manish