After playing with this, this HAS to happen. It's really magical. Probably one of my best VR experiences. You'd think the scales would be off, but things are about as big as you'd expect them to be. Blood Elfs are ~ 6'2, Gnomes look like butch 5 year olds. Seeing a dragon fly by was pretty awesome. The Lich King was like 10-12 feet tall. Various statues around Dal are bigger than you realize in game, but in the right way. Saw an Alliance Gunship flying in Icecrown as well.
One thing I noticed was all the little details that I never payed attention to. Really on everything. Little markings and rune symbols, little pieces of art I never really saw are very apparent. Little things that were ignored before become more significant. I'm not saying it would necessarily be viable to do much more than sight-seeing, but neither was the NVIDIA 3D Vision. This was only in first but 3rd person actually works well in VR as well. It'd be doable to project the UI in front of you and play like that.
I visited Wrath Dal, Stormwind, Goldshire, Ironforge (though it wasn't done), and still need to try the Org one. I'm almost convinced that if a WoW dev were to try this they would push for it as much as they could. I don't know how big of an undertaking it would be, but if it's manageable it would be worth it.
Couple more vids:
SW - https://www.youtube.com/watch?v=317jqyz8wHs
Tomb of Sargeras ship - https://youtu.be/8YexCed0ReM
He's going to do Thunder Bluff too I think.