Abdullah Almuntassir has posted a short teaser video showcasing early development progress with respect to Ultra Weather XP V3.0. The video depicts testing (the first test actually) of the new algorithm which will generates volumetric clouds. Keep in mind, this feature is still very much a work in progress and does not necessarily represent the final result.
You may recall, V2.5.2 is also under development and release is expected much sooner than V3.0.
Anyway, for more information about the current version of Ultra Weather XP, visit the product sales page via the x-plane.org store.