What goes on in the pro marketplace does not necessarily translate to the consumer marketplace. I think that powered speakers have a chance in the consumer marketplace for the reasons Shadorne mentions and also for the fact that they are more neat and tidy for a home decor--no big boxes cluttering up the living room. B&O has been quite successful with this approach, for example, in the less-than-high end, and Meridian and ADC have had some excellent designs using this approach that I think most of us would consider high end. I doubt, though, that those of us in the lunatic fringe (and I include myself in that group) of perfectionist audio will completely embrace the technology, as it limits our choices (no tubes, as Rockadanny gently points out) and ability to "upgrade", and the perception (right or wrong, and Meridian's and ADC's powered speakers make a strong case that perhaps the perception is either wrong or overrated) that constraining an amplifier to such a small, vibration-prone space will be deleterious to the ultimate sound from the speaker.
The disappearance of the traditional amplifier
In the studio and post production world, powered monitors are displacing traditional speakers and amps at record pace. the pro shops as well appear to be abandoning the 'box'. its not like this 'just happened', but is the power amp fading out like a record?