Amazon is again showing that Windows PowerShell: TFM is unavailable. Apparently they sold out of the initial order of books. Last I knew, SAPIEN Press was waiting for Amazon to place a re-order. Given the time it takes to ship books it could be a bit before Amazon gets re-stocked. If you can’t wait, remember that you can buy the book at ScriptingOutpost.com.
As SAPIEN works out additional distribution agreements, hopefully you’ll eventually be able to find the book on places like BookPool and Barnes & Noble. I’ll be sure to post when those agreements are in place. They just take more time than you would think to work out.