Kevin,
You are correct. Edge Detection was a quantum step forward, but it's often "fooled," if one does not have almost perfect contrast (such as the model with fur-trimmed hat, agains a well-lit white background). With that example, one could probably just have easily used Channels to get an almost perfect Mask.
The AE example involves a busy background, and while there is some contrast, it is less that perfect, however the Mask appears to be nearly so.
Regardless, you, and the AdobeTV piece, have generated interest with me. As far as my upgrading again, I must learn to "never say never." 
Guess that Adobe will just keep getting my $...
Thanks,
Hunt