yes BlackBerry and Windows Phone 8 support is on the roadmap, but we cannot provide an ETA yet. Internally, we have prioritized BlackBerry higher, because it uses the same technology (Qt) under the hood which makes it a perfect fit technology-wise and there are not many native apps for BlackBerry World out there yet. With V-Play, your app will run with native performance and without any black borders.
On the other hand, Windows Phone 8 requires core functionality to be provided by Digia. We are following the process of that closely, and as soon as Qt gets avaialable on WP8 we will add V-Play support for it as soon as possible!