Hmmm, I always wonder about things like this.
I'm wondering if G4 is giving up on the video game programming pre-emptively due to the new console generation being on it's way. Every once in a while I hear all this stuff about how intergraed it used to be, and it makes me wonder if the gist of things is that most video game programming is probably going to be through the game systems themselves, so it's pointless for TV to try and compete. Dropping this stuff early in theory would give the hosts doing this now a chance to get involved in/ready for the new format.
I don't really watch G4, and I guess it's been gradual, but it seems like a pretty odd transition overall. With MTV you could at least understand the issues to some extent, only so many new videos being produced (which were increasingly expensive, with little return to the artists unless they sold the viewing rights to the network), and oddly the increasing role of MTV as a sort of youth culture channel, which is what it exclusively became after a while. G4 doesn't really seem to be following a clear path towards transitioning into something else as far as I can tell. Who knows, maybe it's just dying.