Hello Luc Baeten,
Version 3.2 is coming out in the end of January. As for crop and rotate functionality, we do not plan to support it. We will not have a separate Image control for the new module, only a control listing a collection of items. We will, however, provide selectors, which you can use in other controls to select items from the library (similar to the url selector to select CMS pages). So, you can continue extending your control and when the new module is out, you can enable it to retrieve data from the module.
the Telerik team