Stuff I'm looking forward to from the release notes:
* On-Canvas Text Editing
* Cage Transform Tool
* Brush System Improvements
...and all the small improvements that come from a 4-year release cycle.
The big feature I've been waiting for is non-destructive editing, but that's probably for a later release. I can wait.
On the negative side, the notes say that tablet support (such as wacom) might be broken in 2.8. Reading the info at the end of the release notes, it looks like installing 2.8 alongside 2.6 would require more tinkering than I have time for right now.