You can find the full announcement here.  I’ll pull out just a couple of my favorite items from it:

• Includes ability to download scripts from PoshCode
• STA mode support means you can run PowerBoots.
• The current size of the console is overlaid as you resize the window.  Silly little feature, but as it was my idea, you can thank me. 
• PowerShell V2 CTP3 support! This means things like block comments will be interpreted correctly in the editor and console.

To download the beta you will need to register. It’s worth it.