I definitely agree that the "classic TDF-climbs" like Tourmalet, Aspin, Aubisque, Peyresourde, Alpe d'Huez, Galibier, Glandon/Croix de Fer are overused, and that the ASO should try to include at least one stage each year with lesser known climbs.
As for the stage structure I would like to see maximum 8 flat stages that could possibly end in a mass sprint. This is less than they usually use, 9-11 according to Steephill.tv's overview of the stages.
Add 3 ITT/TTT, either two ITT and one TTT, or two ITT and one prologue, that leaves 10 stages for hilly/medium mouintain/high mountain stages.
There should at least one, preferrably two hilly stages with a short uphill finish suited for riders like Gilbert. These stages shoud be in the first half of the Tour.This was great in the 2011 Tour with the Mont des Alouttes and the Mur de Bretagne.
3-4 medium mountain stages with at least one uphill finish at one of these stages. Using the mountains in the Juras, Vosges and Massif Central are perfect for these kind of stages. Stage finishes in Mende, Super Besse, Les Rousses and Belles Filles are good examples in the last years.
Minimum 5 high mouintain stages. Of these there should be at least 3 high mountain uphill finishes. And they should try to use other climbs than the usual suspects in the Alps and Pyrenees. In 2010 we had 2xTourmalet, in 2011 2xGalibier and there is rumoured that Alpe d'Huez will appear two times in 2013. Not very innovativ route creation of CP and the ASO.
I would like to see some of the following stages in the next Tours:
- A Pyenee stage with stage finish at Pla d'Adet, similar to the 2005 stage.
- A stage finsish in Avoriaz after climbing Col du Joux Plane.
- A MTF or a downhill finish at either Mont du Chat or Col du Grand Colombier. This year's stage at Colombier is a waste with a much easier climb after the Grand Colombier and downhill finish from this.
- A stage in the border region to Spain with climbs like Bagargui, Arnosteguy and a MTF to Port de Larrau or Erroymendi.
- A stage in the Southern Alps, example including Allos, Champs and Cayolle with a MTF either at Allos or Cayolle if this is possible.
The are surely more options too, that are more exciting than finishing at Alpe d'Huez after scaling Galibier or Ardiden after climbing Tourmalet.