Love that plane! So we now rely only on satellites that can be shot down?
Maybe.
There's been rumors for years of a replacement for the Blackbird. Aurora is a name that's been bandied about. Whether or not it is true or not, I can't say.
But you gotta figure it would be hard to replace the versatility of a jet you can task to go just about anywhere, any time, and not have to wait for orbits to bring a sat to where you need it.