I'm using Hardy. It seems I was wrong about what icon is used now: If you launch Alacarte, edit the rhythmbox launcher and click on the icon, you'll see that /usr/share/icons/hicolor/48x48/apps/rhythmbox.png is the one being used.
It seems, however, that the launcher is not using the 22x22 version but a larger one, scaled down, which makes it fuzzy.
I'm using Hardy. It seems I was wrong about what icon is used now: If you launch Alacarte, edit the rhythmbox launcher and click on the icon, you'll see that /usr/share/ icons/hicolor/ 48x48/apps/ rhythmbox. png is the one being used.
It seems, however, that the launcher is not using the 22x22 version but a larger one, scaled down, which makes it fuzzy.