I started playing with Monad the other day, and it's awesome! I'm too lazy to go into detail, plus there are more knowledgeable folks out there who've already done that. All I'll say is that even I, who prefer mouse to keyboard and GUI to command line, am excited about this new command line shell from MS. If you ever have had a need to automate something in Windows, you need to check Monad out. If you ever wish you could run code in a command line, you need to check Monad out. If you ever wished Windows had a shell more like a unix shell, you need to check Monad out.
To my friends up at RIM - you guys will love this (if you haven't discovered it yet).