A few distributions are already starting to provide Xfce 4.8pre2 packages whether it be in the official repositories or in testing unofficial ones. I'm going to list them here, use this at your own risk.
- Fedora: work in progress
- Gentoo: can be emerged
- Ubuntu: available in Natty, work in progress
- Zenwalk: available in snapshot
If your favorite distribution has packages for testing, please let me know and I will add them to the list. Happy testing and report all the bugs you may find!
PS: I don't do support for those packages here. If you have any problem related to the packages, contact the person who provides them.