"Sony announced that the PSP will feature upgradeable firmware, via software distribution, as well as anti-skip technology to prevent the UMD from skipping.
Firmware, which is pretty much just software stored in system ROM, controls many of the functions of an electronic device. Sony will provide upgrades to the firmware in order to correct bugs or add additional features. No hint was given as to what those features may be.
The system shock, which will most likely take after the currently used anti-skip system called G-Protection, prevents sudden movements of the system to misalign current lens position while reading the UMD. Not a huge surprise in the inclusion, but none-the-less, good to hear it officially."
Source