Here in Canada, Vonage is really the only one using the term in a direct way. Up here, their slogan is "VoIP with Vonage" - can't get much more direct than that.
Most of the other providers make no reference to "VoIP" or make very little. Even Vonage in the U.S. stays away from the term - they're simply the "broadband phone company".
I'm a marketing guy, and find this stuff fascinating. I welcome others to share their take on this issue - has VoIP become a 4 letter word???
Ping me here, or email me direct - email@example.com