Nikkor AF-S 17-55mm f/2.8

General
This is a lens which has been around for quite some time - it is essentially the professional DX midrange zoom. It's massive, it's heavy, and it's expensive.Very expensive. In fact, so expensive that one wonders if it's worth it.

Pros/Cons
+ superb optical quality. No flaws, really, although I must say I haven't tested it with the newest, 24MP sensors.
+ truly professional build quality, it can take a beating.
+ f/2.8 constant aperture is a given for professional zooms, but this doesn't mean it shouldn't still count as a plus.

- no VR
- pretty limited zoom range, in the end.
- very expensive, questionable value.

Intended Users
Great for:

• if you want the best professional midrange zoom specifically for DX, it's this one.
• weddings, obviously. If you shoot weddings and you're a DX photographer, this is a sweet lens
• if you can be close to the stage, a great lens for low light performance (concerts in dark clubs, theater, etc)

Not for:

• action. It's too short.
• the budget-minded. It's very expensive.
• lack of VR might be a show-stopper for some people.

Final Verdict
In absolute terms, it's a superb lens optically. Its only shortcomings are the lack of VR and the short focal length range. It's of course another story whether it's realistic to expect a professional zoom with f/2.8 aperture and a focal length range of 16-85mm. One that doesn't cost a fortune and weigh a tonne, in any case.

The biggest issue with this lens is its value. It costs a lot, and you have to wonder what you get in return. With the same money you'd spend on this one, you could get the AF-S 85mm f/1.8G, the AF-S 35mm f/1.8, and the Sigma 10-20mm f/4-5.6. This setup gives you more reach and much wider angle perspective, plus the two primes are faster - and at least the 85mm f/1.8 is a bit better optically, too. As always with zooms, the question is whether you want to compromise a bit in everything so that you have the rest in one single lens. Is it worth it? That's up to you to decide.