Update: We're hearing reports that Facebook has killed the beta by making a server-side change which causes the leaked version to display a blank screen.
MoDaCo has just leaked the APKs for the beta version of Facebook Home, Facebook's launcher and app suite that basically turns Android devices into Facebook phones.
While Facebook says Home is only compatible with five handsets, MoDaCo says that the pre-release version works on many devices including the Nexus 4 and Nexus 7 tablet.
Of course due to this being a beta some things aren't ready. The maximum supported resolution is 1280 x 768, and Chat Heads aren't working at all.