Well, you can learn how to play a real guitar with Guitar Hero or Rock Band already it does require a little modification right now to do so but they are developing products as we speak to do so commercially and I can provide proof of this too. As for your previous question that is why you ask friends of yours that have experience with that area to give you assistance based upon their experience. Like if you are having a problem with applying a wrist lock in self defense maneuver from a book or video you can ask a friend of yours that has a background in Jiujitsu, Hapkido, Aikido, or Judo to help you out with that lock and apply it properly on you so that you can learn it and then practice it with your friends.
An example of this is one time I was having a problem with learning how to properly apply a Triangle Choke on someone from my back because I wouldn't put the back of my left knee over my right ankle. But my friend Luis who is a professional MMA fighter came by to see me and he saw that I was doing it wrong and showed me the proper way of performing it to make the person on the receiving tap or get their neck broke. (when he applied it on me I could hear my neck straining and stretching would he cranked on it) Then I rolled around with my friend Chase again and then I got the Triangle Choke again on him and tapped him out (after he punched my face in for a couple of minutes:lol

. You are right that it is always good to have someone that is highly experienced and a trained instructor to assist you with your expertise in the martial arts but even Luis told me that all martial arts share one thing in common body mechanics.
Then just out of curiosity I asked him to look over the martial arts books and videos that I have to help me train with and he actually told me that the joint locks and chokes in the Ninjitsu books and videos I have are the same holds that he was taught in BJJ but just a little tamer. I truly appreciate the knowledge everyone is giving me but I do agree with him because some of the same joint locks in Aikido are also seen in Hapkido and some of the kicks in Tae Kwon Do are seen in Tang Soo Do. So some martial arts styles use the same maneuvers but just call them different names or change them around a little bit. Also I was the victim of him showing me all of the joint locks and chokes from my videos and books with the only comment he gave to me about them was that he just learned to apply these same locks and chokes while standing up or in close range to the assailant instead of being on the ground trying to apply them.
Learning How To Play a Real Guitar with Guitar Hero
http://www.engadget.com/2008/01/03/guitar-wizard-guitar-hero-with-a-real-guitar/
http://www.musicwizard.com/i_can_play.php
http://www.engadget.com/2008/02/07/guitar-rising-perfects-the-guitar-hero-with-real-guitars-genre/
http://www.guitarrising.com/about.html