Thought the show started out rough when it began last September (and I saw a longer cut of the pilot last July), but it's one of those shows that really found its groove, and once it all started to gel it became, imo, one of the 2 or 3 best shows on TV. Acting was a bit subpar and the show occassionally stumbled on its ambitions, but it was a show so filled with ideas and fresh concepts that even my wife became really caught up in it (and she cares not a bit for comics, fantasy, or sci-fi; just compelling storytelling).
I thought last night's finale was a bit of a letdown only because they had to pack so much into it and tie so many loose ends together that they've been developing for the past 23 episodes. The show actually reminded me less of comic books (notably, the X-Men) than of a Stephen King novel, with its many characters developed slowly and often seeming disconected until the end, when everything comes together fatefully. Of course, as much as I dig King as a writer, his greatest shortcoming are his endings, too - but the ride is usually a hell of a lot of fun.
For those who missed this, I highly recommend watching it when it comes out on DVD.