The PowerShell team just posted the announcement late last night. There is a download link in the announcement. This drop has lots of new features like Module support for organizing and loading related functionality as well as transaction support for registry operations using the Registry provider. There have also been some changes since the first CTP so take a look at the release notes.
Let me reiterate the caution that these are "preview" (the P in CTP) bits. There aren’t even consider beta quality although I would qualify that caution mostly applies to the new functionality. That said, I would not put these bits on a production machine. In fact, there have been reports about incompatibility between the System Center Virtual Machine Manager latest drop and V2 CTP bits.
If you don’t have a spare/test PC on which to play with these bits then go grab Virtual PC (free), Virtual Server or VMWare and create a sandbox VM with which to play with this CTP. You will want to create that image based on either Vista SP1 or Windows Server 2008 if you want to take the remote management features for a spin.
One last thing. The Graphical PoweShell is new in this release and is in need of feedback. Folks, now is the time to influence the direction of this feature. If you wait too long the team won’t have time to make anything but very minor changes. So please use it for a while and send your feedback to gPSFback@microsoft.com.