Digitimes is reporting on statements that were allegedly made by TSMC co-CEO, Mark Liu. We are currently seeing 16nm parts come out of the foundry, which is expected to be used in the next generation of GPUs, replacing the long-running 28nm node that launched with the GeForce GTX 680. (It's still unannounced whether AMD and NVIDIA will use 14nm FinFET from Samsung or GlobalFoundries, or 16nm FinFET from TSMC.)
Update (Jan 20th, @4pm EST): Couple minor corrections. Radeon HD 7970 launched at 28nm first by a couple of months. I just remember NVIDIA getting swamped in delays because it was a new node, so that's probably why I thought of the GTX 680. Also, AMD announced during CES that they will use GlobalFoundries to fab their upcoming GPUs, which I apparently missed. We suspect that NVIDIA will use TSMC, and have assumed that for a while, but it hasn't been officially announced yet (if ever).
According to their projections, which (again) are filtered through Digitimes, the foundry expects to have 7nm in the first half of 2018. They also expect to introduce extreme ultraviolet (EUV) lithography methods with 5nm in 2020. Given that Silicon in a solid has a lattice spacing of ~0.54nm at room temperature, 7nm transistors will consist of about 13 atoms, and 5nm transistors will have features containing about 9 atoms.
We continue the march toward the end of silicon lithography.
Even if the statement is correct, much can happen between then and now. It wouldn't be the first time that I've seen a major foundry believe that a node would be available, but end up having it delayed. I wouldn't hold my breath, but I might cross my fingers if my hands were free.
At the very least, we can assume that TSMC's roadmap is 16nm, 10nm, 7nm, and then 5nm.