The French fast line train for the East of Europe (known here as the TGV Est Européen) due to start in June and inaugurated today will bring Paris to Stuttgart or Frankfurt in only 3 hours and 30 minutes against 6 hours previously. Major cities like Strasbourg or Reims will also benefit from shorter transportation times.
I handle this subject as train is a sustainable way to go from a point to another. Taking a train leads to greenhouse gases emissions 22 times lesser than by plane for the same travel. So, enabling people and freight to go between France and Germany faster should hopefully decrease the reliance on plane to cover those distances. For example, Munich will be a possible destination from Paris in December 2007.
Many opponents to the project say that the price is a bit too high compared to other train lines in France. But one should know that this one will be the fastest on French soil with peak speeds at 320 kmph. (around 200 mph).