Maybe just a rumor, then.
I’ve not seen any of the new 3D productions, myself, so I don’t know how “real” the effect is, and whether it adds anything all that impressive to a feature, or not.
If it does, then I’ve got an entire list of old movies I’d like to have reprocessed into 3D, starting with the LOTR.
I have found it highly variable, ranging from indifferent to effective. IMHO "Megamind" made the best use of it.
But movies filmed would probably have to be refilmed with 3D cameras. I'm sure they could be reprocessed as well, but that would require a LOT of work to be done right.