I think it's an interesting idea for a tent, although MichaelW is right to point out that you'd need some very flexible, robust wiring. Also what you say about things doing double duty is a very good way to get your load lighter, and while your idea has a battery pack that does double duty, it also has LED lights and wiring that can only be used inside the tent. Personally, I have a dynamo light, a handlebar-mounted flashlight, and a headlamp. The dynamo light can't really be used off the bike, but the other two can be used around the campground and in the tent. I also have a tiny, LED, Coleman-style lantern that I take car camping or on overnight bike trips when there's room. It does a decent job of lighting up my small tent or providing light at a picnic table. None of those items could be replaced with an LED tent, but most could be used inside of a tent instead of integrated lighting.
So I could see the appeal of that idea, especially for car camping, but I am guessing there would be a net weight increase, not decrease. If you could get one battery pack that powered everything, then maybe, but then you'd be unplugging your tent every time you needed to plug anything else in. Also I don't seem to spend a lot of time in my tent with the lights on. Other people may have different schedules, though, and integrating lighting might make more sense if you spent more time in the tent needing light.