The folks at UMPC Fever got their hands on an MSI X340 and opened it up! It's interesting to see how MSI is able to sqeeze everything to such a slim case, and still have room to spare.
After some prying with a screw driver to lift the keyboard, they were able to access all the necessary screws to remove the casing. The size of the motherboard only takes up a third of the size of the casing. Also, check out the adhesive tapes used to tape down the wires!
Check out the original chinese version, (or if you can't read chinese, the google translated version)