Here's how I look at this whole thing.
It's not Rock and I'm glad it's not Rock. If it were Rock, then I'd be upset. But it's not. He's Aki, and they're making a whole new type of MegaMan series around him, which is the right thing to do. That way, this can essentially be judged on its own, good or bad. This isn't going to take away from the classic series, the X series, or any other beloved MegaMan series. It's a chance for them to get a new generation to spend money on MegaMan stuff, be it games, toys, etc. It's essentially what My Little Pony did, and it worked magnificently. Like Phi & Blue mentioned, plenty of other series have shown off terrible concept art, like Spectacular Spidey (siiiiiiiiigh [tornado fang] you Marvel), Transformers: Prime/Beast Wars, etc. Hell, I was not a fan of the new look/animation of the new Teenage Mutant Ninja Turtles show and turns out it's actually really good.
Also, it's not like there's ever been a good MegaMan cartoon before. Love them as I do, both RS-MM and Battle Network were bad cartoons!