A video of the panel "The Future of D&D" is up. Interesting stuff, despite a few blunders made my Mearls that make me a little nervous (at 7:50 he seems to subscribe to the notion that bad rules can be excused because a "good DM" should be good at patching them, and at 16:40 he indicates an obvious bias by stating that Fireball type spells should be the obvious best choice. Intentional imbalance is NOT good design). Overall though it sounds like the playtest process will have a pretty major impact on the final product so I'm looking forward to its eventual release (which should be soon), and picking things apart.
Those who haven't already (and are interested) should definitely sign up for the Open Playtest. I imagine I'll be using this blog to share my impressions of the new system, and hopefully feedback is still being collected after I return this summer (working out of state, away from my normal groups) so that I can post some actual-play session summaries.