Lightroom 3.4 and Camera Raw 6.4 are now available as Release Candidates on Adobe Labs, adding support for the following cameras:

• Canon EOS 550D (Rebel T3i / Kiss X5)
• Canon EOS 1100D (Rebel T3 / Kiss X50)
• Hasselblad H4D-40
• Olympus E-PL1s
• Olympus E-PL2
• Olympus XZ-1
• Samsung NX11

As Lightroom/ACR PM Tom Hogarty explains on the Lightroom Journal,

The ‘release candidate’ label indicates that this update is well tested but would benefit from additional community testing before it is distributed automatically to all of our customers.  The final releases of Lightroom 3.4 and Camera Raw 6.4 may have additional corrections or camera support.

See the rest of Tom’s post for more info on lens profile updates & bug fixes.