I remember reading Doug Mohney back in the days of Boardwarch, but have not been keeping up with him since then. But the VoIP Princess Carolyn Schuk brought to light some very relevant opinions from Doug related to Voice 2.0:

[Jeff] Pulver wanted purple minutes, minutes of IP traffic part of an enhanced application that might include voice, data and video content. Six years later, Jeff is still looking for his honest purple minutes and innovative applications. Voice 2.0 is here, but there's been no big killer application, it's all just variations of a theme for call forwarding and voice mail and some APIs to slap voice into a web service.

Giving voice an API is, in and of itself, a wonderful thing. We shouldn't discount that development, but I think I have to agree that we're still waiting for that killer app. What do you think?