I want to watch the special again before I make any major comments on it in the other thread, but I think I have some opinions I can make here.
Favorite Autobots:
I think Ratchet is awesome; he's the Geekbot, Voice of Reason, and Endearing Curmudgeon all in one. Sort of like a fun blend of G1 Ratchet and Kup.

Prowl is also a lot of fun. When I initially heard about him, I was like, "A robot ninja? Ehhh...", but his attitude "problem" is interesting, and his Robot Fu is cool to watch. Finally, the quiet, laconic, pseudo-British accent sounds pretty weird coming from a robot ninja, yet it still manages to work perfectly.
Favorite Decepticons:
Holy wow, Starscream is *beyond awesome* in this one. It's like they took all the cool aspects of G1 Starscream without the lame parts. (Actually, I think that's a pretty good summary for the series in general so far.) The last battle where he's busy laughing maniacally and spouting all sorts of pompous, scenery-chewing threats and trash-talking while blowing up the hell out of everything and being generally nasty and dangerous was pure, well, awesome. And Kenny does a good job of imitating the general voice without the screechiness.
Megatron, on the other hand, is almost the opposite end of things: the quietly calm and menacing badass who doesn't need a lot of talk to be really creepy and scary. Burton's voice helps a lot here as well.
Favorite humans:
I like Captain Fanzone. He's a fun dryly cynical counterpoint to the overall seeming "Yay, robots!" attitudes of the rest of humanity. I could see him being an entertaining good-guy-but-a-thorn-in-the-side to the Autobots.
Autobots I didn't like:
Well, none, really. Bumblebee turned out to not be as annoying as he first seemed in the previews (although the potential is still there, admittedly). Bulkhead is sort of endearingly dopey, and I like the younger, more rookie take on Prime, since G1 Optimus' paladin-bot tendencies had me rolling my eyes at times.
Decepticons I didn't like:
None of the other Decepticons get enough screen time for me to say definitively either way. But so far, while Blitzwing's "normal" head is very cool, his "Ahnold" one was kind of lame, and the "crazy" one, well, let's just say that Decepticons should not sing. Ever. The last two personas might have worked in the old series, but they seem out of place in an episode that had far more cute or witty humor than outright goofy humor. Eh, I'll wait and see until he gets more screen time.
Humans I didn't like:
Personality-wise, Sari is OK... she manages to come off as a precocious but fairly likeable kid. But they seriously need to tone down her Mary Sue Powers, or she's going to end up turning into a Wesley Crusher.

Characters I'm looking forward to:
I'll agree that I can't wait to see what they do with Jazz. And on the Decepticons side, Soundwave, of course, and I'm hoping that they make Shockwave less, um, dorky.