I don't think that's going to happen, as promising as that sounds. Cavill is filming Man from U.N.C.L.E.
this fall, have Christmas/New Year's off, and the earliest we'll see him in the cape again is spring 2014. (Then again, WB is running both productions so they can accomodate him to do both if they chose to.) And WB can accelerate production for holiday 2014 -- but they'll have to spend through the nose to get CGI done on time (especially during a shorter post-production time table). Overspending does cut into profit margins.
WB learned their lesson about overspending... they're not going to rush the sequel out. They'll take their time with filming and post-production, just like they did with MOS. I would say at the earliest we'll get MOS2 is spring 2015 since Snyder is already doing prep work and Goyer has already done several drafts. (And if Cavill is ready by January 2014, they'll have plenty of time to make the movie on time and on budget.)
But WB will want to keep this in the lucrative summer schedule, even if its competition is pretty hefty.