In a recent interview (as of yesterday, 19 February) for DellVlog, Mark Shuttleworth says Ubuntu will finally change the default theme from Human to a "light theme". Here is the entire interview:
Unfortunately there is no info on the new theme, but Lucid User Interface (since there is no Artwork drop) freeze will take place on March 4, so we should see it in action very soon!
Special thanks to AnotherUbuntu for the heads up!