Not everyone makes a good amp, digital or otherwise.
It would take too long to describe the technical details that differentiate analog and digital amps so just read this:
http://www.stereophile.com//amplific...729/index.html
There are a number of really exceptional digital amps now available such as the PS Audio HCA2, Bel Canto EvO, and Spectral (or is it Spectron?). They have been used for years in powered subs because of their efficiency. Because they allow transistors to do what they are suppossed to do, which is switch on/off, they waste very little energy (dissipated as heat in analog amps) and consume very little energy on standby (try that with your class A). They are also load invariant so you can drive even the meanest 'stats and planars with them without worry of strain. They are comparatively small in stature and usually don't require heat sinks or venting which is a huge advantage if you are tight on rack space. When done right, like the HCA2, a digital amp can marry the best of solid state analog amp qualities (bass depth, slam, speed, clarity, and extension) with the musicality of tubes (warm, lush mids, airy highs). That's when it's done right...
When there hasn't been enough engineering or parts put into it, digital amps can be horrible. Noisy, hollow, and anestheptic in nature. Their packaging benefits are easy to see (the 35 lb HCA2 simply thumped a 70lb Odessey Stratos) but when the design is skimped on, a class D amp can sound just as nasty as any poorly designed analog amp. In fact, probably moreso because of their efficiencies. Without wasting anything from the source, an abundant supply of clean power is absolutely paramount. I'd be wary about the power supplies that are usually squeezed into receivers.
As far as digital amps future? I'd bet you'll see them becoming a major factor in the next few years. Their benefits are too big to ignore.