He's already stated the days of expecting a new release every 2-3 days are over as the miner is getting close to maximum performance. This fact can be further evidenced by the increase in power draw on the last few releases meaning the GPU is starting to be fully utilized.

Except for bug fixes and new features, expect further performance increases to being in the low single digit percent range with the releases becoming more spaced out with weeks/months in between, much like it is with his Ethereum version.