The majority of notebook computers have CPUs that are permanently soldered onto the motherboard and are not upgradable. This is s especially true of Ultrabooks because their motherboards are so small, there just isn't room for a socketed processor like those found on desktops.
BTW, With Ivy Bridge desktops supposedly delayed until June, we probably won't see the ULV (ultra low voltage) notebook CPUs for Ultrabooks until the fall of this year. Intel always releases desktop CPUs first, followed by regular notebook CPUs and lastly the ULV CPUs.
-------------------- Lisa Gade Editor in Chief, MobileTechReview