I use custom names for my interfaces and it works as long as the name starts with eth or wlan . Thanks Christoph. :)
+ 01 Mar 2013; Christoph Junghans <ottxor@gentoo.org> + google-musicmanager-1.0.55.7425_beta-r2.ebuild: + weaken interface names for warning (thx to Simone Scanzoni, bug #459816)