Bruges to Innsbruck - What's in between?

How many stops do you want to make? Obviously there's much in between. Very roughly estimating, your half-way point would lie somewhere in Germany, either in the Rhineland or Baden-Wurtemburg, although that's a long day of driving.

If we split the trip in half, it should be about 4.5 hours from Bruges, so I'm thinking only one stop. GoogleMaps has us going from Bruges to Koln and then South through Rhineland. Considering our trip back to Amsterdam might take this route, are there suggestions on travel through Northern France or Luxembourg?

Luxembourg City has an attractive old town. Most visitors to Luxembourg (mainly from nearby in Germany, France and Belgium), however, don't come for the history, but for the lower taxed shopping. My impression of the countryside in this small country was that it was quite pleasent, although no one town really stood out from the rest.

Other than Strasbourg and Reims, however, I plead ignorance for this region of France. Just looking on the map, however, there's probably quite a bit of military history (Verdun, Sedan, Marne, etc).

You might get a different routing from
www.viamichelin.com

If its not too far out of the way I would recommend the Mosel Valley.