Looks like a normal new product growth curve:
Roughly 6 percent of all U.S. households currently have an HDTV set that is 3-D-capable — 41 percent of this group do not watch any content in 3-D. Overall, 47 percent have seen a 3D TV, or have a 3-D-capable TV — compared to 24 percent two years ago.
via 75 percent of U.S. homes have HDTV set | HDTV content from Broadcast Engineering.
By 2012, 19% of flat panel TVs being sold supported 3D for a total of 41.45 million 3D TVs sold in 2012. Compare that to 2.26 million 3D TVs sold in 2012.