On ultrabooks: This looks very nice, but I'm a TrackPoint guy, so, while I am excited to see the ultrabooks, I can't use these or MacBook Airs. I purchased a Lenovo X1 Carbon about 2 months ago. It has a TrackPoint and I can't recommend it highly enough. So if you're a Linux user looking for a great ultrabook, check out the X1 Carbon (but make sure to get the 8GB model...)
EDIT: obviously, the X1 Carbon doesn't have the same level of Ubuntu support, but the out-of-the-box experience is perfect.