Worse still, there's more DLC coming in February and March. The one in March will continue the game past the widely-criticized ending (which I havne't experienced yet) and expands the level cap to 30.
Of course, this is all part of the MS strategy: never give anything away for free if you don't have to. They'd make peculiar crack dealers.
Then again, the decision of whether or not to charge for DLC is usually left in the vendors' hands. Bethesda gave some of the Oblivion DLC away for free during a small window, then later would start charging. And then it all culminates in an "Ultimate" pack that incorporates all of the DLC to date for the price of just the original, much to the annoyance of fans who paid for everything piecemeal.