Whither Nikon

Illustration courtesy Nikon
Last week Nikon announced the first of a new series of lenses designed for the reduced image circle requirements of their D series SLRs; the D100, D1, D1X, D1H, and by default the Fuji S1 and S2 as well. This lens is theAF-S DX Zoom-Nikkor 12-24mm f/4G IF-ED(the name is almost bigger than the lens).
This is an interesting development for two reasons. Firstly, it will be welcomed by those that have one of these cameras, as it gives them a lens with the equivalent of 18-35mm coverage on full-frame format. That's the good news. The possibly bad news is that the press announcement states that this is the first of a new series of reduced coverage DX lenses. In other words, Nikon is committing to produce not just this one lens that gives 1.5X factor digital bodies a true wide angle zoom, but also additional lenses in a variety of focal lengths.
But Why?
I have to ask — what is the purpose of these? Once the problem of wide coverage is addressed, why produce...