It makes perfect sense for Abrams to move on to Star Wars. Historical fact, Star Wars has always brought in more money than Trek. Sure he's gonna say all the right things about how he can remain dedicated to both. That's smart and he's not burning a bridge that he doesn't have to. But if it comes where he has to choose, the money is with Star Wars. Plain and simple.
As for what it means to the Star Trek franchise? Well, why should Abrams care about that. He flat out said he wasn't a Star Trek fan before he made ST09, so if the renewed interest his movies generated crashes and burns, what does he care? He's got a great gig either way.