It's a pretty good book, although the ending isn't as punchy as I would like. Endings are hard. It's always tricky to tie up all the loose ends (so that's who did that!) AND have a saitsifying resolution that hints at the future.
My endings are normally too rushed. A lot of what the line editing I just did for my next book (Fire, Kiss, Electric Chair, out from Putnam in 2008, and possibly not with that title) was to give the end a litle more space.