The packages in [community] are cleaned up twice a year. It's this even and the Midyear Cleanup.
The decisions about which packages are going to be moved happens before the 13th of December on the wiki, but the actual cleanup happens the 14th of December, by volunteers.
Christmas Cleanup 2011 was a success, with 9 adoptions and 94 packages moved to unsupported. See the links below for more info.