Looks like the Jetbook is using the interpolation between sub pixels. It also seems that the pixels are printed angled compared to the ipad where they are in a horizontal/vertical matrix.
I think they used part of the OLPC's research, in that they are using the same screen layout of pixels.
Very interesting indeed!
The negative side of having the pixels this way, is that no horizontal or vertical line will seem absolutely sharp, like they do show on the ipad's screen.
And since the alphabet consists mostly of horizontal and vertical lines (see the way characters in a text are written, and how many vertical lines each character has compared to how many diagonal lines), text might be looking sharper on the ipad.
The only edges of characters (letters) I can think of that might look sharp on the color are;
the left side of letter 'A',
top line of 'K' (perhaps),
Right middle line of 'M',
right and middle right sides of a 'V', and 'W',
and if you're lucky the'X', 'Y', and 'Z'.
While the Ipad will show many parts of the alphabet sharp (like the vertical lines in 'BDFHIJKLMNPRTY', and the horizontal lines in the characters 'AEFGHLPRTZ'); though not that it matters that much, as many parts of the characters also exist out of curves, and not only straights.
However, with subpixels, it seems that the jetbook is still capable of showing much smaller letters than the ipad.