U have to look at them from a stripped down laptop pov - these days with even cooler running cpus, and onboard rather than an ati/nvidia scorching ur lap.
The tech really has been there for ages, but with the Atom they're exploiting it that much more.
Notice they don't show u how big the AC Adapter is.
And really, htpc/email/net stuff, they aren't going to replace an enthusiast biased rig.