The UPower source-code was bumped today to UPower v0.99.0 after having the 0.9.22 release earlier in the month. That earlier release brought Bluetooth input device battery support among other changes.
Going back to the beginning of the year there have been plans for UPower 1.0 after Richard Hughes called for the code branching to happen that week, but that never ended up happening yet.
Since the previous release, there's been a wide variety of many improvements to the UPower daemon and library. Some of these changes are covered by UPower on Anzwix. More details on the open-source project can be found via FreeDesktop.org.