For a period, I owned the AF-S Nikkor 12-24mm f/4G, 17-55mm f/2.8G, 17-35mm F/2.8D and the 28-70mm f/2.8D lenses. However, I now use 1.5x sensor DSLRs exclusively, so I felt that the 17-35mm and the 28-70mm were sitting in my cupboard unnecessarily. Therefore I sold them.
On a reduced frame sensor the 17-55mm exhibits a little more barrel distortion at the 17mm setting than the 17-35mm at the same focal length. Conversely, the 17-55mm exhibits a smaller amount of chromatic aberrations when shot wide open (with regard to both the focal length and aperture).
The 17-55mm gets a lot of use on my D2x and D70, so I'd recommend this lens if you want a serious and flexible optic for the DX sensor.
My thoughts regarding Nikon's entry into full frame DSLRs is that if it happens it will probably be accompanied by a new wide angle, full frame zoom lens. This lens will aim to address corner softness, chromatic aberrations and distortion of wide angle zoom lenses. However, I do suspect I'm dreaming.
I also recently sold my 28-70mm f/2.8D, because I found myself switching lenses on reportage work too frequently. Since I bought the 17-55mm I've barely used my 12-24mm f/4G DX lens. I only really use the ultra wide 12-24mm for architectural work. It was crazy hanging onto four zooms that covered a similar range, so two had to go: the 17-35mm and the 28-70mm.
Time will tell if I was right, but in the meantime my insurance premium is enjoying the lighter load.