Sometimes there's not much you can do. It can be the case that, you know business as you know it will end and that no level of investment into a replacement will yield a competitive product (i.e., tube tvs to LED/Plasma, movie rental places, etc).

Even innovation powerhouses can eventually fall. Those that stick around often shed the business units that made them successful initially (GE). One good way to extend the life of a company is to acquire your eventual replacements before they get a shot at you.

Business is hard, and most profitable businesses have a shelf life.