If you hit someone hard enough with it, or in the right place (say... swung at high speed by a 6 year old to your nuts, true story), any lightsaber can hurt you.
Maybe one day, but I don't think they will anytime soon.
Yoda.
1492 When Columbus sailed the ocean blue.
The solid hilt of the lightsabre would cast a shadow, but the blade or beam would not, being only a construct of light or energy.