An early Christmas present is given by the Windows PowerShell team; PowerShell Community Technology Preview 3 of Windows PowerShell version 2.
You can read the announcement by the Program Manager here, and get the bits here.
As stated in the release notes you must first uninstall v1 to be able to install v2 CTP3. Also you would need the Win RM 2.0 CTP 3 for remoting, and .NET 3.5 SP1 for the graphical interface (ISE – Integrated Scripting Environment). Also, you can find a good summary of breaking changes in this blogpost on the Nivot Ink blog.
Regarding PowerGUI the latest build is in general compatible with the new CTP 3 of PowerShell, but there are a few issues which will be corrected in the next version which ships very soon. You can read more about this in Dmitry
With v2 there is a new feature called Advanced Functions which seems really nice, see Jeffrey Snovers post regarding this here.