Unsure whether to buy Point Lookout or not? The latest DLC for Fallout 3 features oodles of swampy, imbred fun, and at first glance, it's worth the price of admission.
If you've downloaded Broken Steel first, that is.
According to a source at Bethesda, part and parcel of Broken Steel is to unlock the level cap and remove the ending of the main game. No other DLC has or will have that functionality. So if you want to advance levels and gain access to the new perks, downloading Broken Steel is a must.