Time Warner Cable carries all 3 in NYC, not anywhere else.
Bright House Networks carries all 3 in their major clusters (Central Florida, Indianapolis, Michigan, Birmingham, Bakersfield)
Comcast carries C-SPAN HD in a lot of markets now, C-SPAN 2 HD only in Philadelphia (city) and some parts of the Southeast.
Midcontinent Communications carries C-SPAN HD in Minnesota and the Dakotas.
I'm not aware of anyone else having it yet. TVguide.com shows Charter in San Luis Obispo, CA carrying C-SPAN HD, but there has been no formal announcement. It may be coming to Charter in the future.