Having been in the industry for a few millenia now, I have seen first hand the ever shrinking computer develop and develop again.
Personally, I believe that work units like the iPad will become the normal computer in the near future, not as standalone units but instead as the front end to processing clusters hosted both in your office or in massive data centers located arounds the world.
And not just iPads, but a new iPhone size device that can be physically stretched into a unit even larger than the current iPad, depending on how much screen space you need at the moment. Think about it, a computer that you can carry in your pocket and use like a phone and music player, but that with a tug here and there can stretch to a screen larger than the monitor on your desktop.
With enough computer power, you could carry parts of your office in the "iStretch" and also able to connect via xG to your office cloud to link to the entire data and document base.
That is what we are coding for today in the upcoming eCandidus™ Workspace system... Now if I could get Apple to release the iStretch.