I doubt they will be able to solve the headaches that comes with doing JL movie within two years. Marvel has a decade on them and hence could do their epic ensemble.
Plus you'd have to have the two film companies to come to an agreement on royalties, cash, etc. Which is unlikely considering Marvel loves having it's own rights.
I didn't say it will help soon, but if you think about it after some Justice Leagues movies have been made (and they are popular as or almost as popular as the Avengers) then imagine how big a JL vs Avengers movie would be.
Just finished watching Source Code and Prometheus... enjoyed both, now going to watch another film...have a choice between Safe House, Contraband, The Goon and The Grey.