Keep in mind that this doesn't enable the feature on your Airport card. It just allows Airdrop to run over whatever other network connection your have. Who knows what havoc it might cause on a workplace LAN with lots of users doing the same. I would imagine there is a reason that was not enabled by default. I can't test that, so I couldn't tell for sure what it would do.
Airdrop was intended to use the ad hoc networking of wifi cards that could do simultaneous wifi and ad hoc networks. One computer connected to another for the transfer, not connected to every other computer on the network. This tip enables AirDrop over the regular network connection, not the ad hoc networking of the Airport card.