I think changing the name of this site will only confuse people and make a lot of them REALLY mad. Maybe instead of changing the name, you could add a subtitle such as "The official YoYoGames forum" or, more simply, "The Game Maker forum." You could also have a link on the main YoYoGames page simply saying "Forums"
Agreed! That's the
exact thought I had before even reading this thread!
GameMaker Community
The Official YoYo Games Forum
I expect that including this in the HTML title and meta (and not
only the logo) would keep the SEO for "GameMaker Community"
plus grab searches for "YoYo Games Forum" -- win-win! This way, everyone can still call it the GMC around the Web,
and any references to YYG's forum will easily lead here, too. $:^ ]
...although now that I've seen the mock-up screenshots for
YoYo Games
GameMaker Community
that looks surprisingly nice. ~nodnod~ Hmm. Plus, of course, it emphasizes the YYG brand, an important point for a company. ~nodnod~
I'm glad that the YYG and GMC are finally being merged. I didn't see the purpose of having two communities in the first place, especially since the GMC had already been in place for years. (Then again, this forum was fairly hostile towards YYG early on, so I can understand why they created a separate one.) All in all, name the GMC anything that fits -- so long as it isn't the horrendously long acronym Nocturne proposed. That would simply be awful. 
I wondered the same for a good long while, too. I had a YYGF account, but with my limited online time, I couldn't maintain time in both; the GMC attracted me more, but I thought it unwise to have two official places for user interaction.
Regards, $:^ J