If we were in a situation where 4E speculation was crowding out all of the other discussion on the forums, then I might suggest that 4E threads should go to a "4E pre-release speculation" forum until 4E is published (at which point it can sink or swim like any other game, but at least the discussions won't be based on WotC teasers, internet rumours and guesswork).
However, even a cursory glance at the topic list in each forum shows that discussion of other games is perfectly alive and well. The majority of active threads in each subforum are non-4E. The majority of active inflammatory threads are about 4E, but then that's only to be expected.
If it gets to a point where I go into the "Role-Playing Games" forum and I have to look carefully to find a non-4E thread, I'd be worried, but it doesn't look like that's gonna happen.