Right, Caroline should be the USA's 3rd entry at Senior Worlds.
Alena Leonova was 4th at Europeans? That is a surprise. Oh why not, she should be the 2nd Russian lady at Senior Worlds (even though she was beat by novice skaters at nationals

).
Leonova is doing both JW and Worlds. The top two skaters at Russian Nationals + Junior Nationals (Sotnikova & Tuktamysheva) are not age-eligible for JW.
Since you asked, Joe:
Ellaj Balde (CAN): Kind of rough around the edges and heavy on the ice, but does have a nice 3A. He's one that needs others to falter if he wants to medal.
Michal Brezina (CZE): He's definitely the whole package. Lots of musicality + a 3A. He's coming back from a big injury, though. He reminds me of Jeff Buttle.
Florent Amodio (FRA): Another guy who's the whole package. If you haven't seen his winning FS from the JGPF, WATCH IT! It's absolutely fantastic. He also has the 3A as well as good spins and great connection with the audience.
Denis Ten (KAZ): Probably one of the youngest men in the field. Very nice skater, great basics, fantastic 3A and nice step sequences. Bit inconsistent, though.
Bariev & Gachinski: Not quite in the same level as these two, IMO. Bariev is fairly consistent and landed a 3A for the first time at Russian Junior Nationals. Gachinski is quite inconsistent and his choreo is nothing special.
Miner, Rippon, Oi: Haven't seen much of Miner, but his Nationals SP was really nice. Oi has wonderful artistry and flow but he's really inconsistent and hasn't quite shown all he can do on the international level. And well, everyone's seen Rippon at this point.
I think Artem Grigoriev, Yuzuru Hanyu and Chao Yang could be potential dark horses.