As you can see from the above screenshot OS 10.0.10.90 is rolling out to O2 UK BlackBerry Z10 owners. This OS is the highest we have seen the last round of OS updates was to version 10.0.10.85, this OS brought lots of improvements including much better battery life.
With that being said one could assume that OS 10.0.10.90 includes those fixes and more. If you got the update and notice anything different please feel free to let us know in the comments.
Thanks to @Jaysus858 for sending this one in!