The people who make important decisions at Blizzard are considering offering up the multiplayer mode in StarCraft 2 as a free-to-play experience, lead designer Dustin Browder revealed during a Valencia eSports Congress panel (via Joystiq). What he actually said, according to PCGamesN, is that the developer is "looking at free-to-play as an option for multiplayer."
When you're talking about a game with a strong eSports community behind it -- a category that StarCraft 2 definitely falls quite comfortably into -- free-to-play can only help your cause. For Blizzard, the challenge is figuring out how to actually do it. Browder admitted that there really isn't any concrete idea of how to monetize a F2P take on StarCraft, since a "pay-for-units" philosophy corrupts the unit balance that the series is known so well for.
Play armchair developer for a moment: given the opportunity, how would you turn StarCraft 2 multiplayer into a free-to-play experience?