http://www.youtube.com/watch?v=tVVCcd37oJE&feature=youtube_gdata_player
What is the purpose of this roll ending with a slap fall? Does bjj roll and stand up as well or do all rolls end in slapping?
By "slap fall" do you mean "break fall?"
Break falls are the methods of landing safely after you've been thrown.
It's necessary to practice different methods of going to the ground and rising.
Rolling forward, backward and sideways to a standing position are necessary skills, and practicing break falls in every direction is also necessary to learn how to land if you've been thrown, and for various sacrifice techniques.
Slap fall. I've been trying to find a band name forever. Youre a genius!