Jackson was silent as to whether the original release dates would hold, but I think we're all familiar enough with the magic of movie making to know that we're unlikely to see The Hobbit in December 2011. Remember, that was the date given for the first half of the film. It's more likely you'll see Part 1 in December 2012, and Part 2 in December 2013.
If you contemplate those numbers with a sinking heart, you're not alone. For me, it's not that 2012 or 2013 are particularly far away (you know how the years speed by the older you get!), but that so much can happen to a film, its writers and directors, and its potential cast members. I'm certain The Hobbit will happen, but it can't hurt to send some geeky good vibes its way, and hope it gains some speed and cast announcements very soon.
[*I've linked to TheOneRing.net, which translated the German interview for the rest of the Internet, and allowed the story to be subsequently picked up in Variety.]