I just saw that the Poppendiecks have a "sequel" of sorts out, Implementing Lean Software Development. I haven't read this book of course -- though I just ordered it.
Their first lean book, Lean Software Development is my second favorite book on Agile (after Agile Software Development). So, I have high hopes for this one. I've mentioned Lean Software Development to several people who hadn't heard of it, so I thought it'd be worth pointed out both books here ;>