Ten One is a New Jersey-based firm that deals with accessories  for smartphones and tablets, with the odd bit of software thrown in for good measure. One of their products is the Pogo stylus, which can't have Steve Jobs that interested--the Apple CEO, after all, is a fan of the finger. However, they've come up with an idea for an app that, if given the thumbs-up at Cupertino, would make the iPad's drawing capabilities a whole lot more amazing.
The software allows artists to draw fatter or thinner lines, depending on the pressure exerted on the iPad's touchscreen. At the moment, only professional graphics tablets from manufacturers such as Wacom  can do this, and they're on the pricey side. Make no mistake, if this were to become reality, there would be a whole lot more budding electronic David Hockneys  than there are now. Ten One has also come up with a nifty idea that lets you rest the edge of your hand on the tablet without the screen thinking that the separate pressure is another part of your oeuvre.
There is, however, a hitch. Ten One is planning on releasing it as a software library to be used by iOS app developers, but the software is dependent on a private function call, and we all know that Apple isn't a fan of that sort of stuff--for it to work, Apple would have to tweak its own UIKit framework, and it is notoriously proprietorial.
Ten One also points out that there's a certain amount of time lag between putting stylus to touchscreen and the image appearing, but they say that it is an issue with their demo app code, rather than their pressure-sensitive library. It's nothing to do with the iPad, no siree, Steve.