Still betting Batista will obviously win. The final four will probably be Batista, Punk, Reigns and maybe Del Rio. Punk will give a "Never Say Die" performance and make it all the way to the end before being tossed out by Reigns (or he'll just be screwed over by HHH or one or more of his henchmen, therefore lighting a fire underneath Punk and intensifying his feud with The Authority), Del Rio will get tossed by Batista either before or after Punk, and then it'll come down to Batista and Roman Reigns. Reigns will have already lasted a long time and probably broken Kane's record for the most eliminations (which may play into Reigns' babyface turn in a small way later if that upsets Kane somehow) and Batista will look dominant (not that he wouldn't already) by being the one to finally take Reigns out.
Regardless of who wins (either Batista, Punk or Bryan), I'm betting Reigns is the last man who gets tossed out. Bryan eliminating Reigns last plays into the whole "David beating Goliath" scenario. Punk going the distance and getting rid of Reigns last bares similarities to the 2004 Rumble a decade ago when Benoit had to enter at #1 and then eliminate the Big Show at the end all by himself (Reigns isn't as massive as the Big Show, but still, similar logic.) Plus, the fact that Reigns is the only Shield member to beat Punk in a singles match will make it that much more of an underdog performance on Punk's part at the end.