The "open government" community has been around since before the Web. In fact, many members were advocating for open-government online before "Web1.0".
So, therefore, if "Gov2.0" is defined by "Web2.0" tools (or even "Web1.0" tools), then it is still an addition to (i.e., subset of) the larger, earlier "open government" movement.
What's somewhat galling (at least to me) is that the late arrivals are acting like Chrisotopher Columbus who thought he discovered a "new world" that, pardon me, was already inhabited by people who he then misnamed as "Indians".
What percentage of self-described Gov20ers have actually read Bill Eggers' book "Government 2.0"?