media-plugins/swh-plugins should not depend on alsa. It also seemed to require the x86 flag, which seems suspicious.
0.3.3 was already fixed, the alsa changes just werent back ported http://cvs.gentoo.org/cgi-bin/viewcvs.cgi/gentoo-x86/media-plugins/swh-plugins/swh-plugins-0.2.8.ebuild.diff?r1=1.2&r2=1.3 http://cvs.gentoo.org/cgi-bin/viewcvs.cgi/gentoo-x86/media-plugins/swh-plugins/swh-plugins-0.3.0.ebuild.diff?r1=1.1&r2=1.2