Created attachment 331776 [details, diff] cegui-0.7.7-irrlicht-1.8.patch thanks to a function rename we cannot build for both irrlicht-1.7.3 and 1.8. I forced <dev-games/irrlicht-1.8 for now, so that ~arch users are not left with broken stuff I'd say do a revbump to dev-games/cegui-0.7.7-r1 and apply the patch (also applied in fedora)
+*cegui-0.7.7-r1 (20 Dec 2012) + + 20 Dec 2012; Julian Ospald <hasufell@gentoo.org> +cegui-0.7.7-r1.ebuild, + +files/cegui-0.7.7-irrlicht-1.8.patch: + revision bump wrt #446410