A peek at a roadmap from Nvidia learns that the Tegra 6, which is developped under codename Parker will actually be a 64-bit SoC. Initially Parker was scheduled for 2015 however now has been scheduled for 2014. Nvidia started developing this ARMv8 64-bit chip late 2010 already and the first samples should be ready by early 2014 as well. 

Nvidia may end up with Tegra 6 chips in phones and tablets by the end of the year 2014, cutting the Tegra 5's lifespan rather short.

Samsung has already acknowledged that it's working on a 64-bit Exynos, and Qualcomm has reportedly been tight-lipped about its 64-bit plans. Intel is already a given, so that leaves Nvidia, which may be forced to accelerate its schedule to keep from lagging behind. A report from ExtremeTech argues that Nvidia may actually release its "Parker" chip, AKA Tegra 6, in 2014 rather than in 2015. This theory is based on Nvidia reportedly having licensed and started working with ARMv8 back in 2010 or early 2011. If that is indeed the case, then the company may have samples of the 64-bit "Denver" CPU cores ready in early 2014.

Denver is Nvidia’s own custom CPU core, based on the64-bit ARMv8 architecture, which they licensed from ARM since 2010, and a CPU core they intend to use from “super phones to super computers” – a phrase Nvidia likes to say many times. Combined with the upcoming Maxwell GPU, that would give them a super streamlined chip product line, because they can re-use the same chips from smartphones, all the way up to servers and even super-computers (where energy efficiency matters).

They’d all have the Denver CPU and Maxwell GPU. That could be great cost-saving for Nvidia. Put all of that on 16nm FinFET, and they would have something really competitive, that other players, especially in the higher-end markets (servers, etc) should really fear.