I don't know if it's entirely legal, but this happens a lot at my home base. When the controller sees that the preceding aircraft has slowed to a normal taxi pace (so it's not going to go around anymore, or crash, or do something else unexpected) the next aircraft is typically given an instruction along the lines of "PH-ABC, regarding the aircraft on the runway about to vacate, you are cleared to land". So far, it has always worked out fine for me.