Generator allows you to create image assets in real time as you work, eliminating the tedious steps of copying, slicing and exporting each layer manually, and saving you hours of time. Simply add a file extension to the name of your layer or layer group, and Photoshop will automatically create a JPG, PNG or GIF from the contents of that layer. If you make a change to that layer, the file is immediately updated. This means that you now have a folder of images that are always up-to-date with your Photoshop design.
If you need larger dimension images for Retina displays, you can also quickly create those by adding a scaling factor.
Adobe Edge Reflow CC Connectivity
Generator also enables a real-time connection between Photoshop and Edge Reflow, the responsive web design application available as part of Creative Cloud. This connection allows you to get assets from your Photoshop document into Edge Reflow with just one click, so you can get started on your responsive design right away.
Open Source, Interoperable Technology
You can install the update by choosing Help then Updates from the Photoshop application.
Read More [via Jordon]