The Tokina seems to be getting favourable reviews all over the internets and looks to be within my price range. Maybe something for next month. I don't suppose the 2mm between the 16mm of the Tokina and the 18mm of my 18-200mm should be a real loss.
You wont miss that range too much. I've used the DX 12-24mm Nikkor glass before, and when I did, I KNEW I'd be using it for very wide angle shots, nothing in the standard zoom range. The lens is pretty purpose driven... I could have really used the f2.8 aperture though, especially for indoor shots!
If you're just looking for something a bit wider than your standard 18mm, you could always consider the 16-85mm VR DX lens, which is sweet!