Mike Mearls' kicks it off right here on Legends & Lore. It's going to be an open development process, there's apparently an early playtest copy that will show up at the D&D Experience later this month, and its apparently going to be as crowd-sourced and public a process as they can get, which is a smart move I think....work with the existing body of gamers, we're the ones who do all the new recruiting, anyway.
Me, I'm just happy they announced it so all the wild speculation and rampant fear-mongering can end. It is a bit ironic that in all likelihood this means that last year's rumors that bounced around were all probably true, more or less.
ADDENDUM: Actually, who knows "how good a thing" this will be....I made the mistake (as always!) of reading the follow up commentary by posters to the announcement. Sigh.....I know that the living, breathing posters of the interwebs are not the same as the normal people who do not spend all their time online bitching endlessly about stuff, but its still bad tidings when the edition war crowd turns so ugly so quickly at this announcement.