Have you checked out the new VADO electric bike from Specialized?
My local bike shop let me test drive one around the neighborhood and it was amazing! My knees are not what they use to be but I was able to sneak up to a team of road racers and with a grin on my face and a light sweat just smile at them as I glided passed. They hated me. I love technology. The bike shop told me that electric bikes comprise the majority of all bike sales in Europe. Maybe Santa will bring me one.