[wisty]

By mobile phone SoC dividend, that's the VideoCore discrete signal processor, right?

From what I can gather Pi has a BCM2763 (as a DSP co-processor to the an ARM, or standalone?) or BCM2835 (combining a DSP and ARM on one chip) ... wikipedia is a bit hazy. (edit: it's the BCM2835 DSP + ARM on a chip, according to the rasberrypi FAQ).

It's got hardware that's dedicated to doing things it's 700MHz ARM chip simply can't, like watching YouTube in fullscreen (obligatory http://xkcd.com/619/). It should be able to do anything a high-end mobile phone can do (except take calls), which is what most people want.

It might be a good deal cooler with a $2 wifi chip (though that might make it harder to manufacture), or a $10 wifi USB adaptor, but I guess you have to draw the line somewhere.