Photoshop CS6 beta is the latest version of Adobe's flagship editing program. Which, conveniently, you can run install and run alongside previous editions (although the 1.7GB download may not feel quite so convenient to some).
The first change you'll notice in this release is the revamped interface. Part of this is cosmetic - it's much darker than before - but there are plenty of functional changes, too. Cropping is arguably easier, properties panels fly out, and there are a host of other optimisations dotted around (the Liquify interface is notably simplified, for instance).