It's just a bigger than a usual tablet PC with a stand.
How about a AIO with a 5870m, i7 730QM, 4GB RAM, 2TB 3.5" HDD.
You know, like a really high end laptop, just not as portable, but with specs that the price can be justified.
Considering you can buy an over-priced Apple iMac that has better specs (with the exception of a multi-touch screen) for way less, I can't see the touchscreen and VESA mounting being worth the $400+ difference.