I have a harder time trying to identify exactly what it is a Printz committee is looking for; I haven't read as many of the past winners and honors, and the guidelines are... odd, to say the least. (They read sort of like an email someone sent out in the middle of a discussion about how a young adult award winner should be chosen (scroll down to "Criteria").
I also haven't read some of the front-runners, like Paper Towns and Graceling. So my predictions aren't worth much. I've read 12 of the 30 suggested on Goodreads, plus I think some others that weren't on that list.
What I Saw and How I Lied (Judy Blundell) already won a National Book Award, which disgruntled many, who think there were better books on the ticket. What fascinates me about this one is that it is, overall, a coming-of-age story--but couched in the terms of a classic film noir. Blundell carries it off beautifully, and it's something new.
Impossible (Nancy Werlin) is not a perfect contestant; it's sort of campy, maybe a little silly. But it's also compelling and fascinating. This is genre fiction that rises above itself.
Nation (Terry Pratchett) is a little muddy; it needs serious polish. (What I Saw is polished to within an inch of its life.) But I don't know that I read any other book this year that captured adolescence so perfectly, in the tentative almost-romance between Pacific Islander Mau and stranded Victorian Daphne. Mau angrily wonders about the validity of religion after his entire society is wiped out. Daphne struggles to live up to the potential she's tried to bury. Really funny jokes lighten the mood and carry the story along.
WHAT I THINK WILL WIN
I think Nation may have a real chance; there's also a whole lot of consensus behind The Disreputable History of Frankie Landau-Banks (E. Lockhart), which I found unremarkable. And there's so much talk about Graceling that I think it must have a shot.
The contender I disliked most was Madapple (Christina Meldrum), which I thought was exploitive and similar in tone and topic to many adult books that no one takes seriously, but it has some strong supporters.
What about The Hunger Games, you ask? I think it fits fine in either the Newbery or the Printz categories; I put it more on the Newbery side, because the treatment of the topic isn't really sophisticated. But I don't think it's good enough (everyone else has already said why: character, plot, etc). I wouldn't really object to seeing it get one of the honors, though, for either medal. It does what it does very well.