From Michael McWhertor's preview: "While the game is still pre-alpha, with an Autumn release date planned - they wouldn't commit to September, specifically - there's a surprising amount of content to play around with, far more so than in previous builds."
"While the game has seemed rather full featured at previous events, including its debut showing at GDC last year, the Media Molecule team is still in the alpha stages of development. The game did lock up a handful of times as Kotaku edited, but the game is many months away. Still, there's already plenty to do and the developer has been staffing up to get the game done. They've gone from a team of 9 last year, to one of 25 today, snatching up talent from Insomniac Games along the way."
"As far as a beta, one is still planned, but given that the Fall 2007 one never materialized, they're keeping dates unannounced."