From the sounds of the thunder, PowerShell RC2 is very, very nearly ready for release. This is the last planned update to PowerShell prior to RTM and contains some significant technical changes ( as well as bug fixes and some detailed feature changes). Perhaps the key change is that PowerShell is now a Windows Component, rather than an add-on application. This means the installer is no longer a nice .MSI file, and the installation folder now lives below the \Windows folder (earlier versions installed into Program Files). This is good news as it means updates and patches can be propagated using Windows Update.
Two small gotcha's. First, if you are using Exchange 2007 Beta 2, don't install this new version. To install RC2, you'll need to de-install the older version of MSH - and this will break Exchange 2007's Management. Secondly, all of the older cool applications that leverage PowerShell are broken and need to be updated.
And while not really a gotcha, if you have any significant PowerShell scripts, you may need to schedule some testing as the language/product changes may cause some earlier scripts to stop working. This is especially true for any Exchange 2007 scripts you may have written (e.g. you need to change the extension from .MSH to .PS1).
PowerShell's RTM date has not been divulged formally, but a betting man might look at the calendar and work out the next significant Microsoft conference and decide to celebrate PowerShell's RTM with some sun, sand and sangria. And even though Barcelona in the late autumn can be cold and rainy (from my experience), I'll sure be celebrating when RTM happens!