Not sure if everyone knows this, even if it seems obvious, but assuming Battle.net and your internet connection are functioning normally you can still gather a bunch of dudes in the same room and 'LAN it up', even if you are all connecting to Battle.net to create and run the game.
Assuming it works as intended, and you are not interested in 'stealing' the game, this setup should only provide additional advantages (compared to straight LAN play).
From a technical perspective, it seems stupid to send all that traffic over the internet and back when the guy is sitting right beside you. Somebody needs to validate how much of an issue this may cause for the average internet connection. We need somebody to set up a 4 versus 4 match of the beta, where all 8 computers are using the same internet connection, and not only see how well it runs but measure how much bandwidth it uses both upstream and downstream.