Progress on the next major revision of UrBackup is documented in the Testing forum. You can click on the word Testing in this message, or select it from the list of Categories on the Forum home page.
Generally posts about Server 2.5.xx/Client 2.5.yy from Uroni describe the progress on the current test build and how to participate in testing the new features.
There is also a Developer Blog, linked at the bottom of the www.UrBackup.org home page.