DRE, as with any release of a version (ie 1.2.0 B5 -> 1.2.0 RC1) it is bug fixes and stability improvements. Change logs are not released for unstable versions as they are stable versions.
Don't know if it was mentioned before. The avatars in threads are now embedded with img tags contrary to being embedded with CSS. This was accomplished by adding img="true" to xen:avatar.
Code:
<xen:avatar user="$user" size="m" img="true" />
The difference now is that Google can pick up the avatars and index them.
I don't like the way the height is limited and requires a click to expand. I like to make it easy to read posts and having to click to expand quotes is a PITA.