Here are my guesses for the 5 discretional American WCs (I'm assuming that Odesnik will make direct entry):
Jesse Levine (this is probably a certainty)
Brendan Evans (even after that
in Indy qualies. Regardless, he's young and is top 200)
I have no idea who will get the remaining two. If Kuznetsov and Sweeting get their crap together during the next few weeks then they'll probably get them, although considering how they've been playing I don't have much faith in them right now.
McClune is another option. He is young and will probably develop into a good player, but he really hasn't done anything notable this year.
Smyczek showed some potential earlier in the year but hasn't done much since. I doubt he'll get it.
Dent's comeback is just starting to get off the ground and I don't think the USO singles draw is on his mind (he mentioned possibly doubles). I'd love to see him play the qualies. If he wins a challenger or goes deep in a US Open Series event I bet he'd reconsider, though.
Warburg wouldn't surprise me. He's ranked fairly highly and I think he's been pretty active with the USTA trying to promote the sport. Perhaps they might return the favor.
Amer Delic has an ok chance since his ranking is fairly good. He's had some decent results recently although he's been inconsistent. As with Warburg, I think he's been pretty good to the USTA.
Here is some longshots IMO:
Michael Yani has been playing well and when he was younger actually had some decent potential but has suffered from injuries that have prevented him from taking off. If he can reach the finals or win a challenger in the next couple of weeks I wouldn't be shocked to see him get one.
Rajeev Ram has also been playing well, including a win over Santoro recently. As with Yani, even though he's not young anymore, if he does well over the next couple weeks I wouldn't be shocked to see him get one.
Kei Nishikori wouldn't surprise me either (if he doesn't make direct entry), considering he plays a lot of American tournaments and trains in the US. He's young and certainly capable of competing at that level. He also got some WC's into American tournaments earlier this year. I know they don't have a track record of giving foreigners WC's, but he's certainly an option.
Somdev Devvarman might be considered too, since he's much better than his ranking suggests and has been playing well. I wouldn't be shocked to see organizers give the US College system some love.
Although they have good potential, I doubt that Ryan Harrison, Rhyne Williams, or Chase Buchanan will get main draw wildcards unless they win Kalamazoo (Ryan Thacher is entered too
). Bradley Klahn could easily win as well.