The disappearance of the traditional amplifier

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.

Rcprince brings up the typical objections to powered speakers. However, when carefully examined, the advantages of active speakers with active crossovers will far out weight the drawbacks. And, what is too frequently overlooked is that not all active speakers are powered speakers with built-in amps. The active speaker with outboard amps provides both the superior performance and the choice of amps, cables, and the option of experimenting all you want.

vibration-prone space will be deleterious to the ultimate sound from the speaker.

It certainly would if you used tubes. In that case you can still go active but they would need to be 'outboard' amps dedicated to each driver (this would still make the design active and is actually how active speakers started)

Active loudspeakers are IMO long overdue for penetration into the consumer marketplace - there's virtually no aspect of amplifier, loudspeaker, or crossover performance that isn't improved by using a separate amp for each frequency range with the crossover being performed before amplification.

The main reason that it isn't more common is both cultural and economic. For starters . . . loudspeaker companies and electronics companies have different resources and abilities - speaker companies are usually mainly woodshops, and electronics companies stuff circuit boards into sheetmetal enclosures. Most of the companies that build active speakers rely on an outsourced "plate-amp" module (either off-the-shelf or custom) that's easily incorporated into their conventional design/manufacturing methods, and most electronics companies that have loudspeaker lines outsource the cabinetry from a woodshop.

In an economic sense, if you're going to integrate two things together, the receiver/passive-speaker has some clear advantages over the tuner-preamp/active-speaker combination -- putting like things together affords considerable savings. (Look at a cheap mini-system with biamplified speakers - the amps are always in the main unit, with two sets of speaker wires.) For custom home installation, it's also much cheaper to run low-voltage speaker wire everywhere, than to use a high-quality balanced line-level distribution system, plus AC power at every speaker location.

And there's also the cultural difference in the distribution side - it takes much more thought and effort for a salesperson to convince somebody to replace their amplifier(s) (that they may be attached to) when they're looking at making a speaker purchase. And in the high end, there are many symbiotic relationships between amp and speaker companies, that share resources at shows, and serve the same dealer network -- an active speaker product can upset these relationships.

But although I feel that the active speaker approach is in general a better way of doing things, I still think that there are a LOT of really poor products in the "professional" ranks, even some very high-priced ones . . . i.e. I feel passive ATC SCM20 or SCM50 (or even the old JBL 4435 running passive) absolutely smoke the now-ubiquitous active Genelecs. And don't get me started about the cheap "active monitors" (really overgrown computer speakers) that mail-order music stores ship by the truckload . . .

Vibration is hardly an issue *only* with tubes. Every single type of electronic component exhibits decreased performance in a high-vibration environment.

A passive crossover is not a big deal if it's simple, as it should be for many other reasons. My experience has proven that they can be far less destructive than running the tiny, low-level signal through an active crossover of any type - a necessary evil with any type of multi-amping.

I have found that most people who are so enamored with powered speakers are those who tend to be impressed by measurements over subjective sound quality and tend to listen mostly to the processed, modern music that masks differences in electronics quality in the first place.

I'm sure there are counter-examples.