You have to wonder at what point they can't make it any smaller right ? TSMC R&D head Shang-yi Chiang said volume production of 14nm chips is expected to happen in 2015. Additionally, he also reveals this process node will use 450mm wafers:

Taiwan Semiconductor Manufacturing Company (TSMC) will conduct R&D for 14nm process technology starting 2012, and expects to begin volume production on the node in 2015, according to Shang-yi Chiang, company senior VP of R&D. TSMC will use 18-inch wafers to process 14nm chips, said Chiang, adding that manufacturing with larger wafers helps increase its ability to produce at a lower cost.

The transition to larger, 18-inch-sized wafers will also allow TSMC to build fewer fabs, meaning that labor and land costs can be reduced, Chiang pointed out. In its ongoing advanced technology development, TSMC is actually facing a shortage of engineers rather than technical issues, Chiang added.