It sounds interesting, especially the weapons, and I hope they make a proper single-player campaign for it. I think it would have been wise to keep the original look, though. From the screenshots, it looks just like dozens of other games, and for this to succeed, they need something that stands out from the crowd.
They mentioned two modes: a full story mode, replete with sidestories for each character, and some unnamed mystery mode that they'll reveal at a later date. So there's that.
And while the cartoon style will be missed, the game does look great, and the environments still have that Insomniac feel. They showed off a few pictures of the different locations, like snow-covered mountains, middle eastern temples, and lush, vibrant jungles. I wouldn't worry too much, I think they got this one.