It's difficult to tell from the photo because it doesn't give much indication of the puppy's size. To hazard a guess though I'd say either a Great Pyrenee or a Kuvasz.
Hard to say without a size guide, but I would also guess Golden Retriever x Collie. Though I'm not a designer dog fan, this does make a really good cross - Retriever bid-ability with the Collie work ethic. A lovely puppy - I'm quite jealous!
I'd actually say something a lot smaller....maybe spaniel mix of some kind. How much does he/she weigh?
My guess would be golden retriever or Labrador crossed with some kind of spaniel, most likely cocker or springer.