That's right, now that the Rage of the Firelands is upon Azeroth, the Alliance and Horde are going to need all the help they can get. Thankfully, the free trial -- which previously spanned 14 days -- now lasts indefinitely, though trial players are capped at level 20 until they purchase the full game. Do note that the Starter Edition does not include Cataclysm content but does include some Burning Crusade content such as the ability to roll Blood Elves and Draenei. And for those who decide to upgrade, the World of Warcraft Battle Chest (which includes vanilla WoW and The Burning Crusade expansion) is on sale for a paltry $19.99.
And of course, there's more to patch 4.2 than the Starter Edition, and our sister site WoW Insider has your bases covered.