Hi, There's a new Rhythmbox release in town, 0.9.4.1 was released on April 25th. Using ebuild for 0.9.4_p1 seems to work fine after renaming to 0.9.4.1.
Created attachment 87743 [details, diff] Patch to make rhythmbox compile against >=libnotify-0.4.0 This patch is the upstream fix. Please bump.
Added this to the tree yesterday, sorry it took so long.