Yep - there is a reason Wacom tablets are still so expansive. You wouldn't be able to get that resolution at an iPad size for cheap enough - but it is only a matter of time (now that there is a higher scale of demand from Apple and other tablets)
They also have an insanely high threshold for parts quality, but without the volume to keep manufacturers making the same parts, they keep running out. The new Cintiq[1] has one of the nicest displays you'll ever see, but it will likely always be in short supply.
the component cost of the touchscreen in the Asus is around $40. I have the larger model here. the component cost for the wacom touch interface and controller (which you can't even really buy) would be in the hundreds of dollars (for a 7").
if you have used a real wacom you will know what I am talking about, the feeling and accuracy is simply awesome. I can't wait until the technology makes it into consumer tablets
they are doing a lot more integrations now, though most are pen: