You can use the 1.5 nikon lenses on full-frame, if you want to live with an reduced image circle. While this implementation is far more user friendly than canon EF-S, its not ideal.
Please do enlighten me to what's not ideal about being able to use my already paid-for DX format lenses on my D3x- because it seems pretty ideal to me to not have to always carry a second body to use something I already own- and if I'm doing it, I obviously (a) don't have the angle of view covered in FX and (b) am willing to accept a 10.5MP image as the result.