The Panasonic AG-HVX200 is due out in 6 months, but I see no planned Vegas support for the codex and file formats this camera used. I know Sony is big on HDV, but surely they won't use this to prevent Vegas from supporting this.
I believe the wording about Vegas 6 is to the effect that it will support all *currently* available HDV decks and cameras.
Having said that doesn't the MainConcept DVC-Pro and Mpeg codecs work for it? To the best of my understanding the codec that Vegas has is the same core codec. I think many of us outside of the developing side have talked about this for a while. Adobe also uses the MainConcept codecs as well. If you compare version numbers they all come up somewhat the same. For example in the newest Premiere HDV update (1.5.1) the 2005 MainConcept codecs come up as versions "1.3.43.0" and "prerelease build" on the mpeg side. For those with Vegas 6 maybe check the codec versions just for the hell of it.