If I had to guess, A57 devices will hit the market in mid-to-late 2014 at the earliest. TSMC hasn't announced that the 16nm FinFet fab is production ready yet. Once that happens, Nvidia and Qualcomm have to get some samples and determine how to implement/modify these cores into their SoC design. Additionally, while the A57 will be produced using the 16nm Fab, the the transistors on the chip will be 20nm according to Engadget.
By the time these chips make it to the consumer, Intel will have already pushed out 14nm products. Judging by the fact that Intel is opening up it's Fab to outside businesses (possibly even Apple), I would assume they will have additional production space to create 14nm SoC's soon after the release of "Broadwell". Intel just got it's feet wet in the smartphone space, but I think it will be a heated battle; Intel vs ARM by 2015.