What are you still doing here? Oh, you want to know why this is awesome? From John Nack's blog:
Lightroom 2 adds a Retouch tool right within the Develop module (see screenshot). That means you can paint regions of the image to dodge, burn, saturate/desaturate, adjust contrast, and more. Edits are stored as metadata, just as all other LR adjustments are stored, and are applied directly to your raw images. (Because people will quickly ask, I'll point out that unlike Apple's newly released Aperture 2.1, Lightroom integrates its selective editing tools right in with the other adjustment tools. In Lightroom you don't have to generate a TIFF file for editing, and unlike in Aperture, you can always tweak the results later. In addition, Lightroom features Auto Mask technology for tweaking the clicked region without bleeding into neighboring areas.)
I just became a better photographer.