I think the answer to this is a deffinite no. But it may be the wrong question.
Will Ultrabooks replace desk top PCs - that, I think, is a yes - except for embedded computing where we still need a box computer system with lots of I/O.
What do you think?
Just watch Star Trek: Next Generation for a glimpse of the future! They use Ipad clone tablets for reading or light work, but for serious stuff they sit down at their touch panel consoles