Nikon, like most companies, follows government-mandated repair policies in the US. That means that they keep parts for no more than (usually) seven years after a product is no longer available new.
That means that the F6 and FM-10 are the only two cameras for which Nikon is currently stocking parts; the next "newest" film SLR is the N75, which appeared in 2004 and lived for only a short time in the Nikon lineup.
So it's highly likely that if your Nikon film SLR fails, you may have to look to other than Nikon if the repair requires parts. We still have a handful of camera repair shops around that have the repair manuals for the older Nikon SLRs and scrounge parts from other cameras that aren't operating (obviously, for reasons other than the part that is used for the repair).
But frankly, given that you can pick up used F100's in excellent shape for less than US$300, when film SLRs bite the dust these days it is usually just simpler and cheaper to purchase another used camera.
