Yes, it does, see:
(actually, see the second one first).
As for your second question, I haven't run Linux virtually on the mac, but I HAVE run windows (with both VMWare and Parallels), and there is quite considerable performance degradation, in my experience. The Chromebook supposedly runs linux at native speeds. The LTE is clearly a win (I am typing this in a New York City hotel, where I am using my iPad's hotspot functionality, but this is clunky (and I HAVE to have multiple devices with me). The display hardware is significant for me (I stare at my screen too much, and get tired on lower res devices). Otherwise, I don't disagree, the hardware is pretty generic except for the LTE and screen.
1) VMs don't degrade performance very much. Modern CPUs have virtualization features built-in that make them excellent options. In fact, many corporate servers are virtual machines that they can seamless move between physical servers without it ever skipping a beat. I'm quite a fan of XenServer and iSCSI specifically for this type of ease of use and redundancy.
2) You inferred that you're running two OSes at the same time on the same HW. That means it has to be a VM if you are actually running two OSes. Crouton clearly shows that you're switching between two UIs for a single OS that is running. That is not two OSes as you can tell by how quickly it launches without any bootstrap or other aspects of the OS loading. It does, however, help prove my earlier point that Chrome OS is built atop a fully accessible Linux substrate.
edit: The Ubbuntu UI is running in its own space (wondered how they were going to deal with that) but it's still running on the same single boot. It's more complex than simply running different GUIs like you can do with Gnome and KDE, but it's not that much different. The changes all look to be made to convert the Linux boot to simply allow the Ubuntu GUI to start as needed. A clever proof-of-concept but it's not going to make waves do to its many shortcomings.
3) What Linux distro has a GUI that is designed for the Chromebook Pixel display at this time? I'd guessing none at this point. This is an area where Linux is likely very slow to move.
Edited by SolipsismX - 3/24/13 at 9:36pm