Intel markets the Atom processor for netbooks. It trades lower processing power for very low power consumption, and is quite inexpensive in large quantities. These are product features where ARM/PowerPC/MIPS have long focussed, though they have aimed at non-PC form factor devices. Now, a new round of small laptops is hitting the market using non-x86 processors with either Windows CE or a Linux software stack like Google's Android or, eventually, Chrome OS. Most notably, Dell appears to be on the verge of introducing such a device - the true measure of whether a product category has entered the mainstream. These devices are generally called Smartbooks, owing to Qualcomm's extensive marketing push for its ARM Snapdragon chips in such a role.
What strikes me about these devices is that we've been down a similar road before. In the late 1990s there was a flurry of activity around HandHeld PCs, which were relatively small and inexpensive compared to the laptops of the day. They typically used MIPS processors, ran Windows CE, and supplied basic word processing and communications software. Handheld PCs didn't last long on the market, and Microsoft ceased work on the software after just two years. The devices simply were not useful enough when compared to a full laptop.
This is another example of how infrastructure and market can make more of a contribution to the success of a new product as its design. If a product is too early, it won't get enough traction to drag the rest of the environment along. In 2009 these devices can depend on a fast wireless infrastructure and plentiful cloud-hosted applications, which did not exist in 1999. The world has changed.