Lightroom 2.5 and Camera Raw 5.5 are now available on Adobe.com and through the updaters in Photoshop CS4 and Lightroom 2 (choose Help->Updates).
Camera Raw 5.5 replaces the original one that was installed with Adobe Photoshop CS4; Adobe Photoshop Elements 7; and Adobe Premiere Elements 7 software. Visit the Camera Raw page for a complete list of supported cameras.
Lightroom 2.5 update includes additional camera support for several new camera models including the Nikon D3000 and Olympus E-P1 as well as several fixes for issues introduced by previous Lightroom 2 releases. Buy Lightroom 2.5 here