Adobe today released an update to their Photoshop Touch app for iPad. The update finally ads Retina display support and smooths out the navigation and animation a bit. Full details below:

Adobe Photoshop Touch 1.3 Update

Retina Display Support
Even Higher Resolution Capabilities (up to 12 MP image size)
Two new Effects: Shred and Colorize
Smoother animation and scrolling in the organizer, tutorial browser, and file picker
New three finger tap gesture to toggle 100% view and fit screen
New pixel nudging mode for precise movements
Support for Apple Photo Stream**
Various bug fixes

source: Photoshop.com Blog