I have a couple of things to add on this topic...
I read through the majority of the posts and it didn't seem to come up in discussion that video games are highly addictive. There have been a number of people in my family that have become addicted to video games and have missed out on important chunks of their children's lives, and their own lives (yes I'm talking about adults). My point is that even in a very relaxed unschooling home, I cannot allow full unlimited access to any type of addictive substance. Yes, children need to learn self-control, but you wouldn't give them another type of controversial addictive substance (like alcohol, cigarettes...) and expect them to just "learn" self control on their own at such a young age.
My husband and son (7.5 yrs) both love gaming, but DH set a "rule" of no screen time during the week apart from certain computer sites/games that we approve of (we are pretty loose on those and allow games like battleship, monopoly, etc. but limit simple mindless shooters, etc.). He still is limited in the time he spends on these games/sites because we feel that he needs to have outdoor time, time to read, etc.
We are very relaxed unschoolers, but we see everyone in our home as equal (not the same, but equal) and so we all get computer time, relaxed reading/quiet time, etc. SO, our son is "free" to play games at times, BUT if someone else needs the computer for work/play or needs/wants quiet time, then he has to adjust his behaviour to suit all of our needs. If he impedes on the quiet time, he has to go outside. I definitely believe in "freedom, but not license".