I just searched the internet and found a negative answer; the D90 is not yet electronically connected to the lenses. I'm in the process of selling my 200-500, if you're interested - you'd just have to buy another body; I still have the Nikon D7000.... maybe we can get into business... (dallwe@gmail.com)
The lens is compatible as it also has the F bayonet. However, it is designed for the FX format and is therefore actually too heavy and too expensive. But it does work.