I feel like that by identifying Percy as the leader of the Greek camp, it's solidified his place as part of the seven. I can't see Annabeth going anywhere without him although I'm afraid RR's gonna kill her off :S but between her and Nico, she'd probably get kicked out. It'd be more interesting, imo, if she was the only one out of the three that became part of the seven.

I definitely like Leo the most out of the three new kids. My affection for Piper comes and goes, but I think the reason I'm annoyed with Jason is because he's automatically awesome and we don't get to see that. We get to see Percy develop into awesomesauce over the course of five books; Jason did all that developing in the background and is just remembering that it's happening.