The current development kernel is 2.6.39-rc2, released on April 5. "It's been an uncommonly calm -rc2, which should make me really
happy, but quite honestly just makes me really suspicious. You guys are up
to something, aren't you?" See the
long-format changelog for all the details.
Stable updates: the 22.214.171.124 update
was released, with a long list of fixes, on March 31.