I own an HP dm4 (http://goo.gl/uCRa) running Ubuntu 11.10, it's not an ultrabook, but everything run out of the box and all working (except fingerprint device - which I don't care a bit about it). HP in my case has been always a choice, their products work excellent with linux and just right out of the box. I recommend you also, that you make sure that everything is Intel (including the wifi card) because previoulsy I had another HP laptop with Atheros wifi that was unusable!