In the most recent Independent Characters podcast, Carl Tuttle mentioned that there are two playtest groups that he's aware of. One is codenamed The Mournival, and does rules/competitive playtest -- I believe that's the one that the Nova and FLG guys are a part of. The other is called The Infinity Circuit, and comes at playtest from a more casual, narrative point of view and includes people like his group (Carl, Adan, Justin), Loopy (from the Masters of the Forge podcast, and other stuff) and a few others I don't recall.
I think it is smart for GW to come at playtest from both sides. Parsing the two streams of feedback can't always be easy, as 40k has a pretty complex history (in-game backstory, playstyle and edition wars) but I'm glad they're at least trying to address all the styles of play.