The fledging market for ultra-mobile devices (UMD)—a catch-all term that includes ultra-mobile PCs (UMPC), netbooks and mobile Internet devices (MID)—is already complex and will become more complicated as it grows. A few salient forecast numbers may serve to guide vendors and investors as they negotiate this tricky landscape. According to ABI Research principal analyst Philip Solis, “Total revenues earned by vendors in the UMD market are expected to increase from $3.5 B in 2008 to nearly $27 B in 2013.”

This year, retail sales account for only 14 percent of shipments, while UMDs provided by mobile operators stand at nearly 30 percent; the balance are sold directly by manufacturers. Over five years, however, that distribution mix will change significantly.

Operators currently subsidize UMDs for the sake of their potential service revenue, but they would prefer not to. By 2013, only 20 percent will be operator-provided, while retail sales are expected to account for 75 percent.

In 2013, more than half of all UMDs will have x86 processors at their heart (largely Intel’s Atom), with the balance based on ARM processors. When it comes to operating systems, in 2013 Linux will outnumber Windows devices by two to one across all UMDs, despite the higher return rate for Linux products (compared to Windows products) experienced by netbook vendors today.