Funny. This mentions seeReal, but fails to mention their prototype holographic displays, which, on paper at least, are way cooler than their autostereoscopic displays.
But... Yeah, we have a long way to go yet.
Although, mentioning ARquake, I suspect you can create your own implementation for a modest budget of $1000-2000 if you make use of a laptop, cheap GPS tranciever, and cheap VR glasses (Vusix comes to mind; They even have AR variants of their glasses, and some models have 6 axis head tracking as well.
Add in a few wii-remotes or similar... Well, cheap it isn't, but the costs are low enough to be managable to anyone that can afford to put together a high end gaming PC.)