Think I still prefer my vaio pro
The vaio pro has 1080p screen, weighs less than this, currently is selling for £950 with a pci-e SSD, no vents on the bottom so it won't overheat sitting on your lap or the bed.
The toshiba has better battery life and that's about it, if you want more battery life on the Sony you can get the battery slice and I think it will still only weigh slightly more than the Toshiba. Toshiba should get points for providing upgradeable memory. This shows it is possible on a lightweight machine.
Also as Graham has mentioned above, not just Sony but Toshiba themselves were producing a machine R500/R600 that is lighter than this but included a DVD drive.