According to a Forbes article, IDC said only 350,000 umpc have been sold thus far. That is not mainstream. What is needed to be mainstream is a umpc that breaks the typical 7" screen and provide a smaller more mobile device that can fit into a jacket pocket which is up to 4.25" x 7.5" x 1.25". Something ideally with a touch type keyboard built in and offers the touch screen. A device more like a modern Psion would be what mainstream business users would buy.

The old Psions and HP Jornada's sold over 2.3 million per year back in the 90's. If UMPC companies modernized that form factor coupled with the UMPC ability to run full windows; now you have a mainstream computer that the enormous laptop market would buy. A good percentage of laptop users do not need a super fast computer and if it was jacket pocket size they would love to buy that over a bulky laptop. That is what is needed for UMPC's to be mainstream.