E-assist bikes are hugely popular for touring in Germany right now, and there is impressive infrastructure in certain areas to support it. In the Black Forest region, for example, there is a network of charging points (restaurants, cafes, museums, retail stores, etc.) that offer free charging points. These are noted on trailside signs as well as maps you can get from the tourist offices. Tourist officials and tour providers realize the potential of a huge market for people who might not otherwise try bike touring, and are investing in making it viable.

Here's an example: • E-Bike Region - Touristikgemeinschaft Hohenlohe e.V.

And in Austria: E-Biking in Austria and especially http://www.e-bikewelt.com/en with a network of 1000km of trails in Tirol.

Also, now that there are well-designed E-mountain bikes, I'm seeing them now being used in the Alps for guided tours and also rentals. Expensive bikes, though, around 2500-3000 euro.