For me, Spa seems more ordinary every year. With the tremendous grip of the modern F1 car, it appears, and sounds, as though even Eau Rouge can be taken flat out. What is the challenge in that?
IMHO, the only way to restore Spa and indeed, F1 as a whole, to its former glory is to dramatically reduce downforce. They could start by reducing the width of the front wings so the endplates (along with any appendages attached thereto) cannot extend beyond the inner wall of the tyre (when the tyres are pointed straight ahead). Not only would this greatly reduce overall downforce, because the rest of the car would have to be altered to compensate for the loss of front grip, but would, at least to me, vastly improve the looks of the cars.
This reduction in grip would also make the driver a greater part of the equation than is he now, and I see nothing wrong with that!