The KEYWORD for this ebuild has "-* amd64" so it won't build on x86, even with ACCEPT_KEYWORDS="~x86". I moved it to /usr/local/portage, modified the ebuild to be "x86" for the keywords and then installed it. As far as I know this part of xfce4 is stable but at least needs an ~x86 keyword also.
I marked this build -* because it was a snapshot that became unmaintained and was/is broken after RC3. I personally know how buggy it is and has the possibility of locking you out of your WM. This is scheduled to be officially released with xfce and there may be work done in cvs, but until then I want to keep it marked that way for my maintainace sanity :)
I have been marking this build ~x86 (which i run) for months and have encountered no show stopping problems. How about getting the ebuild changed to reflect that it works (for me anyway) now?