Here be SPOILERS...
Okay, so now that I've seen the movie, my opinion has changed has certain potential purchases.
Sideways: I thought this guy might have some meat to him, if only 'cos of the cool name. But, what, 16 seconds before being cut in half?
Wheelie: Less annoying than I feared. I'm more tempted to buy him than I was before, despite the leg humping.
The Twins: Same as above.
Jetfire: I was one of the supporters of him before, but now I MUST have him. Grumpy, nutty Bill Nighy-type old man? Done.
Soundwave: I'm less excited than before about this guy. Like, he sits in space humping satellites and being a voyeur. Not too exciting, Soundy.
Ravage: Awesome. I don't think I was going to buy him before, but he's great in the movie. Love him.
Optimus: I'm not the world's biggest Optimus fan, despite all the people raving about the new toy. But the awesome moment in the woods protecting Sam? Yes. Must have. Plus, if I'm getting Jetfire I should get him too.