As someone said above, the stations with xl (xplicit lyrics) beside them are unedited. There are several unedited. There are several good channels also. Not all pop crap.
Actually, NOTHING is edited on XM radio. If there is any mat'l that contains naughty words it only gets played on a XL station. As far as editing mat'l so it can be played on a NON-XL station, no they don't.