What's new from release notes
- Multiple homepages
- Sidebar remembers its state across sessions
- Download fixes
- History improvements
- Accessibility improvements
- Size and memory reduction
- Performance improvements
- Stability improvements
- Better Windows appearance
- Many more new themes
- Too many fixes to list
See below for detail.
http://www.mozilla.org/projects/phoenix/phoenix-release-notes.html
Phoenix is a redesign of the Mozilla browser component, similar to Galeon,
K-Meleon and Chimera, but written using the XUL user interface language
and designed to be cross-platform.