According to this Tech On! report, Nintendo are in the process of evaluating their Wii Remote accelerometer technology. Seeing if other companies can supply better gear than their current suppliers can.
One firm - Kionix - definitely can. Currently, the Wii Remote's accelerometer sensors are provided by two companies: Analog Devices and STMicroelectronics. But Kionix employ different technology, which makes it "easier to enhance sensitivity".