Technology is constantly changing, even our cameras. Many upgraded to DSLR's and have settled down, but the usual DSLR's are so bulky to carry around. People carry around a Point and shoot for normal use but that has also changed, since they can get DSLR features with Compact DSLR Camera's by Sony.
If you were fortunate to buy a NEX, and still got a bunch of Good lenses that you've used with your bulky DSLR by November you will be able to get your hands on this nice adapter which you can use to attach your existing traditional DSLR lenses (like Canon, Sigma etc) to your compact NEX. All thought they wont keep your camera compact anymore, but you could use lenses from your other DSLR lens collections.
This won't be that cheap, it would set you back around 480$ in November when it is released.
I think it's a good upgrade for someone who has a NEX, and would want to use the lenses which he has lying around from his other DSLR's. Especially if he has some Macro, Fisheye etc lenses of his DSLR, and doesn't want to spend on some new lenses for his NEX.