There has been some talking on the Windows PowerShell in Action Manning forum about a new PowerShell book titled "Windows Powershell in Practice". Windows PowerShell in Action by Bruce Payette was fantastic. Personally, it was and still my PowerShell bible. I'm sure the new companion book will be as exciting as its big brother ;-)
Bruce comments when asked when the book will release:
"Windows PowerShell in Practice" is a new book that is in development at Manning. I'm not sure when it will be available. It will cover things like the PowerShell SDK (writing cmdlets, providers, embedding the PowerShell engine in other applications, etc.) as well as larger, more domain specific examples and advance scripting techniques.
I'm not currently a direct contributor (but I do kibitz on occasion.) Jim Truher (who co-designed the language with me) and MOW are working on this book. I'll ping them and see how it's going...