- Downloaded the beta ISO image: ubuntu-12.04-beta2-desktop-i386.iso
 - Made the USB boot from ISO using usb-creator-gtk
 - Started from USB with "Try Ubuntu" option
 - Installed Skype
 
Results:
It took a couple of attempts to get the screen resolution right (no changes - just that many times the screen boots in only 1024x768 mode).
Also the screen is flickering slightly and I filed some 3-5 bug reports (popup kept informing abt. several background crashes). (bugs.launchpad.net/bugs/972294)
All this allowed me to try most of the gadgets. Working:
- Display
 - Audio (with keyboard volume control/mute / Fn+F2,F3,F4)
 - Webcam (with Skype)
 - Trackpad (with edge scrolling)
 - Bluetooth (with Skype)
 - Youtube video/audio (full screen working but rather laggy/chippy)
 
- Keyboard display light controls / Fn+F5,F6 (adjusts ok but has no effect on display)
 - Multitouch trackpad (never got that to work with Ubuntu before either)
 - External display/VGA (nothing happens when connecting a monitor, keyboard switch / Fn+F7)
 
CPU/fan noice is irritating (saddest part of the Vaio X) but I must say that it's behaving and the fan shuts off completely from time to time. Running nothing but a Youtube clip spinns it up though.