World of Warcraft: The Burning Crusade Now Free, New Digital Battle Chest

Not only has Blizzard Entertainment slapped up a World of Warcraft Battle Chest compilation pack for the low price of $19.99 over at their digital storefront, but they've also made all of The Burning Crusade's content available to every legitimate World of Warcraft owner free of charge.
Haven't yet ventured beyond the Dark Portal? Beginning today, June 28, players will be able to get both the original World of Warcraft and the game's first expansion set, The Burning Crusade, for only $19.99 as part of the new digital Battle Chest now available in the online Blizzard Store. In addition, anyone who owns the original World of Warcraft, regardless of when they purchased the game, will automatically be able to access all of the content and features from The Burning Crusade expansion at no additional cost. It's time to set forth from Azeroth, adventurer -- Outland awaits!
This is a great deal, sure, but I'm actually a bit surprised that they haven't done something like this sooner.  It's the $15/month they're primarily after, right?