Pressure-sensitive stylus support for iPadAdobe Photoshop Touch is available on the App Store for $9.99. [Direct Link]
We added support for three of the most popular pressure-sensitive styli in this version of Photoshop Touch: the Pogo Connect, Jot Touch and JaJa Stylus. Using the special capabilities of these devices, users can draw, paint and retouch their work in Photoshop Touch with a more natural look and feel. At this time, these styli support iOS only. We’ve also improved our brushing engine to make smoother strokes with or without a special stylus.
Apple will introduce new versions of iOS and OS X at its annual developer's conference.