I registered my daughter, and she received her invitation the other day. Set up her Desire on our laptop, not too bad, just had to ensure the latest HTC sync is installed for driver purposes. I had a run through the first simple tutorial, and we now have a miowing cat app on her phone! Very easy. App Inventor is still work in progress, but is fun and a great entry into app development. I need to have a proper play to try something clever-ish, not a programmer though!