Windows 8.1 Update 2 RTM'd not too long ago, which means a release date is close. According to PCPortal, Windows 8.1 Update 2 will arrive on August 12, but you probably won't even notice. Update 2 is rather insignificant compared to Update 1, meaning nothing has changed on the surface.
It's entirely plausible that Microsoft won't even announce Update 2, and instead just push it silently with Patch Tuesday. Update 2 is said to include bug fixes, under the hood changes, and a few tweaks that you probably won't even notice.
Update 2 was originally going to include the new Start Menu, but Microsoft decided to pull the feature and save it for Threshold. Update 2 will include no new features, and will most likely be preparing for Threshold when it launches in 2015.
Update 2 will be the last 'major' update for Windows 8.1 until Threshold launches in 2015. Microsoft is now done with Windows 8.1, and all focus is on the development of Threshold, which has recently been coming into light. Microsoft is expected to talk more about Threshold either later this year or next year, as a Preview has been rumored to be making its way to the public at some point later this year.