Let's get the easy ones out of the way first.
Forward center, a Green Lantern: Oh, you know it's Hal.
Two o'clock, a Green Arrow: I'd love to see Arsenal, but it's far more likely to be Connor.
Top, a Hawkperson: Look at that headpiece. It's Hawkgirl.
Top left: Given his vapor trail, that almost has to be Red Tornado.
Top right: Bulleteer.
Right center, behind Superman: Zatanna. Second thoughts: Vixen.
Above Zatanna, to the right of Batman: That silhouette is so generic it could be almost anybody, but given all the talk about a Teen Titan "graduating" into the JLA, I'm thinking it has to be Cyborg.
Biggest surprise: No J'onn J'onzz.
Biggest disappointment: No Flash. Second thoughts: I was really hoping for Jessie Quick.