As technology moves forward, we are going to see companies that never competed against one another vie for market share in what is going to eventually become the vast middle ground between a full functional PC and a basic low-end cellphone.
The world's largest handset maker, Nokia, is already off to the races, indicating their intention to move into PCs:
Nokia's CEO Olli-Pekka Kallasvuo says his company is actively looking at the market for notebook computers as smartphone and computing continue to converge.
In the mean time major PC makers, including Acer and Dell, have already entered or will soon be entering the cellphone market.
Where the segment ends up, I think, will be a function of display and data entry technology. Flexible, folding displays are already being shown in the back rooms of many technology companies and will be here soon, allowing larger displays to be carried in smaller formats. MMI (man-machine interface) is still an issue, however, and the segment will be segmented for a while between a full keyboard and some other data entry mechanism that allows a smaller unit, until some breakthrough is made in this area.