I feel that the last episode was a bit weird, but I'm ultimately happy with Spear's arc. The "big fight" was lame on it's face, but I think it was always a macguffin. Ultimately, he had his hero's journey, and redepmption arc as it was- and he did quite well at it. I think the complaints would be less if they did an extended episode for the finale. Which given adult swim- they could have fit another 15 or 30 mins in with little problem. All that said, the second series was great, and a little bit more violent than I was expecting for Adult Swim- all things considered.
Also those Baby dino's are absurdly cute.
It seems to be very wrapped up. But you could easily anthologize it again after the finale, but another time setting seems more likely as the poster above implied. I've been a fan of Genndy for ages, so I hope he continues making more "adult" stuff. He's certainly made all the fucktons of monies with the Sandler Transylvania movies and really shouldn't have any immediate budget concerns.