Last week Toshiba showed off a new, lower power version of the Cell processor under development for mobile phones. The advancement pairs well with the natural shift to 65-nanometer production technology from the 90nm line currently in production for the PS3, but it sounds like Toshiba is the only one actually pursuing the Cell for mobile purposes at this time.
The question remains, however, at what point is the Cell no longer the Cell? In addition to shrinking the technology, we may see the processor altered in additional ways for power consumption. My guess is that we will see a lot of "Cell" products that are about on par with the competition, even if the original processor is as powerful as Sony, Toshiba and IBM claim.