Current preupgrade?

[BeartoothHOS]

	Some weeks ago, when preupgrade led or could lead to F15 Beta, I 
tried it and got royally snarled up. I never did get Gnome3 to boot 
properly on that machine, and finally installed Scientific Linux, which I 
also wanted to try. (I like it.)

	I'm thinking I might want to try F15 again. I got a look at it 
with Gnome3 by running a live CD -- and didn't do very well. So I'd like 
also to be able to run Xfce instead of Gnome3. Is there a way to do that?
Alt-F2 to gnome-terminal to root to "yum install xfce," maybe?
-- 
Beartooth Staffwright, Neo-Redneck Not Quite Clueless Power User
I have precious (very precious!) little idea where up is.