The intent is not to just change the place where we discuss things.
Generally I believe it's a way of giving an actual home to the protocol that is not bound to Google or any company.
It's also a way to organize the community in a way that no-one can be road block for too long...
Finally, I believe the scope of this group may be broader than just PubSubHubbub and think about a more general PublishSubscribe pattern for the web that would fit more people's need than just social, RSS or Atom feeds... I hope people that are not involved with PubSubHubbub but who created their own PubSub protocols can also participate in establishing a new protocol that can later encapsulate PubSubHubbub as it is now.
Julien