Ryback would play very well in New Japan, but they're currently very thick with largeish muscular gaijin. I'd imagine someone will eventually want to head stateside for a bit, so there's no reason for them not to add another, it just might not happen immediately.
Alex Riley stuck around the WWE for a number of years, and you don't do that if you're a complete idiot about professional wrestling. He just has almost no facial recognition. There's a job out there in the mid-tier echelons of professional wrestling if he wants it- it just might not be in front of a camera. He brings a lot of experience to the table, and that's valuable in and of itself.
Hornswoggle + El Torito: If they want to stay in professional wrestling, it's tours of indy shows in their respective countries. Otherwise, it's into our hearts and memories; never forget WeeLC.
Wade Barrett has said he's stepping aside from professional wrestling, and I have no idea what other projects he has going, but the natural transition away from that is into broadcasting or acting. He's got a job in any other promotion if he wants it; he's a case of the WWE screwing up a good thing.
Cameron is probably done with professional wrestling. Best of luck to her in whatever she chooses to do.
Damien Sandow would work out well in ROH; if TNA is still throwing money at people to achieve the same steady decline in their viewership, I'm sure he'd take it. Not sure if he was unhappy in the WWE and that's why they stopped using him so much or if the WWE just dropped the ball, because he was the natural successor to Santino Marella's act at the time.
Dutch Mantel (Zeb) either enjoys his retirement, or works for whichever promotion is willing to pay him enough to keep working.
Santino's out of professional wrestling now, and if he was smart with his money, enjoys his retirement from professional wrestling with a project he's passionate about.