This news comes straight from John Nack's blog:

Lightroom 2.7 (Mac | Win) and Camera Raw 5.7 (Mac | Win) are now available as final releases on Adobe.com and through the update mechanisms available in Photoshop CS4 and Lightroom 2. These updates include camera support for the following models:

• CanonEOS 550D (Digital Rebel T2i/ EOS Kiss X4 Digital)
• Kodak Z981
• Leaf Aptus-II 8
• Leaf Aptus-II 10R
• Mamiya DM40
• Olympus E-PL1
• Panasonic G2
• Panasonic G10
• Sony A450

Release Notes:

• Camera Raw 5.7 includes an updated demosaic algorithm designed to provide compatibility with settings applied in Lightroom 3 beta 2.
• Lightroom 2.7 also includes the same updated demosaic algorithm. The updated demosaic algorithm will appear as a subtle shift in noise characteristics at default values.
• By default Camera Raw will display the image adjustments exactly as performed in the Lightroom 3 beta 2 develop module. However, at this time Camera Raw 5.7 is unable to support further adjustments to the following settings or tools:
  • Highlight Priority and Color Priority post-crop vignette
  • Enhanced Luminance and Color Noise Reduction
  • Grain effects
  • Process Version