User Interface: WASD, Arrow Keys or something else?

Enterprise users are not usually gamers, like the users of applications like World of Warcraft.

What user interface do you think is best for basic movement in a virtual world? There are three "standards" AFAICT:

- WASD with mouse ("Quake style")
- Arrow keys (walk and turn)
- Game pads

WASD has been honed through the years by avid gamers to allow control of both movement direction and look direction. However, it means that the keys on the keyboard can't be used for chatting by just typing.

Arrow keys are used in a lot of casual games, and even some not-so-casual games. It appears to be fairly natural to newcomers, but does not have the look control of WASD+mouse.

Last, everyone seems to "get" a gamepad once they have their hands on one, but PCs don't come with game pads, and "game" pads still have a lot of entertainment-only stigma to it, so even if it would be the perfect input device, would it gain acceptance? (One ray of hope: in the military world, game pads seem to have acceptance as a bona fide input device)

Do you have opinions or experience in this area?