I'm mostly interested in battery life. At present mine is exceptional.
Some of the good things that were present in earlier test versions, such as the display white balance adjuster have been culled. No doubt due to manufacturer pressure.
Not bothered about third party AOD notifications but double tapping to wake would be good rather than constantly having to use a hard button.
Some more audio settings such as bit rate choice etc would be handy too.
I guess most of it will be in I'm ally different to MM and what we've already got with TW.