Bungie co-founder Jason Jones said something recently that, depending on how you choose to look at it, could have been taken at best as an inaccurate assessment of the control preferences of the PC gaming market.
It's sparked an interesting to-and-fro between two websites, Ars Technica and Rock, Paper, Shotgun, the former declaring the "keyboard and mouse are losing the FPS market", while the latter predictably offers a very convincing rebuttal.
If you've got any stake in PC gaming at all, it's worth a few minutes of your time to catch up on it all. Start with the Ars piece first.
Mouse & Keyboard Still A Major Player In FPS Market [Rock, Paper, Shotgun]