Don't know much about it other than the url cited above and some earlier publicity about the project that came out a few months ago. But I find at least one aspect of the promotional material misleading and that makes me skeptical about the entire approach.
Using a capacitive stylus, the width of a mark is not determined by the width of a stylus tip. It's determined by the app being used. If you doubt this take any conventional stylus and make a mark on the iPad screen with any of the many drawing/note taking apps that allow you to set the width of the line. Then do the same with your fattest finger (try your thumb.) You'll find the width of the lines is identical.
The capacitive screen of the iPad requires a certain activation diameter (designed for a finger tip) to enable a mark. The mark itself is at the center of this circle. Some styluses with larger tips may obscure the "contact point" but that does not result in a larger contact point or a wider "mark."
Frankly, I find the video to be misleading in this regard. It's obvious, I think, that the wider marks shown by a capacitive stylus are the result of changing the width of a drawing app, not the greater accuracy of the iPen.
Furthermore, as the video demonstrates, the "iPen" requires an attached receiver to locate placement of the pen. Likewise, it requires a note taking/drawing app to use the signal rather than the capacitive placement to locate the contact point. This may well have advantages such as palm rejection compared to the capacitive stylus (at least theoretically) but it is neither more accurate nor does it result in a finer line when drawing.
By the way, I'm not defending the more conventional (and considerably less complex) technology used by most styluses. Apple took a low cost, simple approach and then defended it as "superior" by arguing that one could use a finger rather than a stylus. That is clearly arguable. But the iPen approach requires just the sort of "add on" technology and hardware that Jobs sought eliminate in the iPad. And it does so without really adding much functionality.