I started reading the Archie Sonic comics when I was a kid and I'm still reading them - I have a totally complete collection (excluding reprint collections). So I'll absolutely be getting this, because now I feel like I'm honor-bound to keep my collection complete! I might be about twenty years older than the target audience, but I still like reading it every month (actually twice a month, there's a spin-off called Sonic Universe) even if the quality is occasionally less than stellar.
I started reading the Archie Mega Man series, but stopped before too long. It's pretty decent for a children's comic, but I couldn't justify the cost of keeping up with it. But now that it's going to cross-over with Sonic, I might get back into it.
As for the quality of this, I've got high hopes! I doubt it's going to be anything life-changing but Archie's editorial staff has improved pretty drastically since the days of the NiGHTS comics. Fortunately, that writer hasn't worked for Archie in years. Also, I'm pretty sure Mega Man and Sonic both share a lot of the creative staff, so combining them shouldn't be too awkward.
Regardless, it's guaranteed to be better than the last Archie/Sonic crossover!