Programmable input devices are so pervasive in PC gaming that it would be absolutely stupid for MMO (or other game) publishers to ban for their use. These companies have marketing agreements, cross promotions, etc, even though the input devices are specifically designed to do things that some people feel are against the rules of their favorite games.

Example: http://www.razerzone.com/swtor/keyboard - this is a SWTOR licensed programmable keyboard, you get an exclusive in game item, the game client must have some support for it "Up to 16 million customizable colors, which also respond to actions in game", etc. Look at all the marketing! They want you to use this. Imagine if you bought one of these puppies and then BioWare banned you from SWTOR for using it. Your immediate response would be for both Razer and BioWare to go fuck themselves for leading you into this trap. And you could probably sue over it.

Now let's go one step further. Any product competing with the above product, such as the Logitech G13, must be allowed to compete fairly, so they can't ban you for doing the same thing you would have done with the Razer keyboard, with another product, unless they would also ban you for using the Razer keyboard.

Anything else would be highly unethical, possibly outright illegal, and if it were me, I would probably challenge it legally. They simply can't promote these activites/products and ban for them at the same time.

So anyway, there's my rationale. It's been this way for a few years at least. I'm not sure this issue is as relevant as many of you make it out to be.