I tried to find the official feature list of new Ubuntu release. Could not find it with my favorite search engine and not in the Ubuntu-wiki.
I want to see if systemd is included. I could find a lot of blog posts about it, but not an official feature list or roadmap.
For each new release there is a cycle of definition then freeze of features that will or will not be included. Anything discussed before that date is premature and may change.
Usually Feature Definition Freeze will be some weeks after uploading the toolchain followed by a definite Feature Freeze approx. 2 months before the final release.
The schedule for the next version is not yet published but you may have a look at the schedule from the last release (Utopic Unicorn release schedule) to get an idea.
This is why at present there will be not yet be any "official" feature list.