According to their Source blog, DC will be brightening up their universe in 2010, just like Marvel is doing. I'm very intrigued at the possibility of a streamlined DCU boasting a brighter, more positive tone.
There will be a new bi-weekly series called "Brightest Day" that is essentially DC Universe: Rebirth, from what I have read. The series will be written by Geoff Johns and Peter Tomasi, with covers by David Finch. The creative team will be rotating.
A number of DC titles will carry the Brightest Day banner too, I guess representing low-bummer content? The announced titles so far include The Flash by Geoff Johns, a Deathstroke-led Titans book by Eric Wallace and Fabrizio Fiorentino, and Justice League of America with a new lineup.
I'm very intrigued. I had planned on waiting for trade for all this, but I'm not sure I'll be able to hold off on all of these. At the least, I'm hopeful that Brightest Day might feature Martian Manhunter, Blue Beetle, or Aquaman and Mera.