Today, on , Blizzard explained the controversial decision, stating that they wanted to encourage more use of the Battle.net service and safeguard against piracy in the future:
"We don't currently plan to support LAN play with StarCraft II, as we are building Battle.net to be the ideal destination for multiplayer gaming with StarCraft II and future Blizzard Entertainment games. While this was a difficult decision for us, we felt that moving away from LAN play and directing players to our upgraded Battle.net service was the best option to ensure a quality multiplayer experience with StarCraft II and safeguard against piracy.
Several Battle.net features like advanced communication options, achievements, stat-tracking, and more, require players to be connected to the service, so we're encouraging everyone to use Battle.net as much as possible to get the most out of StarCraft II. We're looking forward to sharing more details about Battle.net and online functionality for StarCraft II in the near future."
While it may not have LAN support, the first entry in Blizzard's planned StarCraft II trilogy, Terrans: Wings of Liberty is planned to arrive on the PC by the end of the year, with a public multiplayer beta expected this summer.