Microsoft is currently investigating ways to modify the Xbox 360 controller, with a possible view to releasing a 'finer-tuned' version of the device in the future.
According to a report on Shacknews, Microsoft's Robert S. Walker - product unit manager, hardware - has recently revealed how the company is peering at the controller's right analogue stick and mulling over how it could be designed to better function in genres that require very precise movement - e.g. first-person shooters.
When or if we'll see such a revised controller is topped by a pretty hefty question mark however - apparently, such a device is a maybe rather than a definite at this stage. But if it does see the light of day in months to come, it's a peripheral that would be released alongside the standard 360 controller as an optional purchase rather than a replacement.
Would seem like a fairly decent move to us and with Gears of War and then Halo 3 on the horizon, a revised FPS controller would be just the ticket for hitting them right between the eyes.