The failure to recognise the touchpad and fallback to identifying it as a PS2 mouse is due to the hardware using a new protocol and the manufacturer not releasing the specs so that a free driver can be written.
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/550625
The protocol has been mostly reverse engineered and there is now a fix involving a patched kernel module, but it isn't completely perfect (won't do multitouch) and hasn't yet found its way into the mainstream kernels. See the discussion for details. It also tells you how to do the patch if you feel brave enough to patch your kernel.
If all you want is to be able to quickly and easily disable the touchpad so you can type, then try setting up keyboard shortcuts as follows.
xinput --set-prop "PS/2 Generic Mouse" "Device Enabled" 0
will disable the touchpad while
xinput --set-prop "PS/2 Generic Mouse" "Device Enabled" 1
will enable it again. Being able to turn the touchpad on and off with a simple key combination makes the problem bearable while we wait for a better solution.