I really like the recent trend in American animation towards films that do not follow the regular Disney formula, ie Prince of Egypt, Iron Giant, Antz, Toy Story, etc. Japan has been producing un-Disneyish animated movies for decades, but it is nice to see the American studios doing it as well.
I loved the look and feel of Titan AE; its visual style was rather unlike anything I've seen before. It was reminiscent of anime, but not at all identical. There were also some neat SF ideas, such as hydrogen trees, a cracked moon, and a machine that can create a world (yes we've seen that before in Star Trek 2 and probably elsewhere, but it is still an awe-inspiring idea).
However, the writing still felt so space-opera standard. The plot was driven by ray-gun shoot-outs, ugly-looking bad guys, a hip young slightly rebellious protagonist,and generic SF action lines like "Go ahead; I'll cover for you" and "Eliminate the humans!"
Titan doesn't deserve to be a blockbuster, but it's entertaining and I hope it is just popular enough to let Hollywood know that animated SF films can make money... opening a door for potentially better ones.