Considering the Mac App Store is the way they’re distributing OS X Lion developer builds, I’ll give this a big: no shit.
Looking at their mocked-up screenshot though, I am curious as to how quickly Snow Leopard users will upgrade. I’m guessing much faster than if they had to go buy the disc at a store.
And I wonder what the price will be? Given how much Apple has shaved off software like Aperture and soon Final Cut, I’d bet Lion will be pretty cheap. Perhaps the same $30 price as Snow Leopard?