ARMv8 is the upcoming 64-bit compatible architecture. This commit talks about adding support for ARMv8, so it is likely that Android will be adding 64-bit support. Qualcomm has already announced a 64-bit SOC, the Snapdragon 810.

Also, they talk about API level 20 which is one level higher than Android 4.4.

There's been work on 64-bit Android for a while now. https://android-review.googlesource.com/#/q/status:merged+64...