I honestly doubt they will add LFR in cata. The devs most likely broke it when they tried to make it into a 10man version. Now they have to fix it. Here is what was said in a blue post.
With the introduction of LFR gear through multiple alternative avenues(this means more than 1), it is logical to determine that there is no valid reason for LFR to be released in Cata. It would be better for the devs to address and fix the issues they caused when they attempted to change it and then release an unbroken version in MoP.