Hi Laurent, I really enjoyed the session while I was at MIX, thanks again for the talk, code samples, and MVVM Light! Speaking of MVVM Light, one thing I've been wondering about ever since attending your talk is which version of MVVM Light to use for new WP7 projects that will be submitted to the marketplace in a couple of months. I noticed that V4 is currently out as a Preview release, which you likened to a CTP, but I wasn't sure how much time it would take to get to the Production release. Basically, I'd like to use some of the cool new V4 features (e.g., your IoC container), but I'm afraid to do so if it means that I may run into some serious "Preview Release" bugs that cause us to have to delay the release of our WP7 app. Sorry for the vague nature of my question, but any guidance you can provide on which version of MVVM Light to use in the near-term would be greatly appreciated. Thanks!