If you try to emerge XWine without gnome-libs, it simply proceeds, but fails afterwards because it can't find gnome-config which is installed by gnome-libs. Adding gnome-libs to the dependencies would be a nice fix :) Sorry for not providing a log, I simply emerged gnome-libs and tried again :)
The XWine-0.2.2.ebuild has been updated and should be available on rsync servers within 24 hours. emerge rsync emerge XWine The dependancy list has been updated, changed to econf and einstall, and added support for nls and gnome use variables. All compile problems should be fixed now. Please test and report back on this bug.