here is one explanatin for the update (from the Amazon forums)
LInky
http://www.amazon.com/2-K2-firmware-...sin=B00154JDAI
Initial post: Mar 4, 2009 6:53 PM PST
lsmcenter says:
There's a noteworthy improvement in the joystick function. They've added a working "acceleration" algorithm. Hold it for more than a second and it speeds up. If they attempted same in the 2.0 firmware, it didn't work as well.