@AURON570: The mystery of the Titans is one of the big sticking points for me as well on this one.
Regarding the length and if it will cover enough of the manga to be interesting... I really hope they take the route of giving us a fully fleshed out arc for the series and try NOT to follow the original pacing of the story. I don't mind them not covering the whole storyline (ala BERSERK) but it would suck to have more of episode 3's in our future because that was not nearly as strong as the first two. If I wanted Top Gun with giants I would've... oh, I guess that show doesn't exist.
Either way, still pumped about this one. Something about the horror elements being done in this show makes me wish there was a good anime interpretation of Uzumaki out there. Limited 13 episode show of the short stories from it? Oh yeah, I'd watch that. And then never sleep for like two weeks.