Ha! I'm a dope. In my shortcode, I had previously set "author=false"
Having said that, I think this is a great step in the right direction. However, I should note that the value being returned is technically the user or channel name, and not the author name. For example, look at this gallery from a playlist I just put together at random:
http://testground.cr...t/divine/video/
Those are user names (and one is a channel ID for a user who apparently didn't set a user name for his channel yet!):
mrchilloutbear
G96frjyMVUSQSGiJzb58VA
andyfieldmagic
aliasmike2002
1eruanis
shedscience
However, on the actual playlist, here are the author names, respectively:
Chillout Bear
The Dumping Ground
Andy Field - Card Trick and Magic Teacher
Keep It Underground
MindMastery
Sally Le Page