Eh, I'm not too keen on this. It just seems too...easy, I guess.
Up until the recent post-"Death Of" relaunch, I've read every single Ultimate book. Everything put out, good and bad. I never once thought "This would all be better if it crossed over with the 616." What I liked about the universe was that it took chances. Some worked, some didn't. But it tried new things with old characters without the stigma of screwing up what people considered the "real" characters.
Within that context, this just comes off as lazy. It's what everyone's expected since the universe started. Doing it takes away from that unique feel of the Ultimate universe.