SIP Communicator is still under active development and its first real release approaches. In order to learn the exact status of the development you could check out the SIP Communicator Roadmap or join the announce mailing list. In the mean time you could try one of the following nightly builds.

SIP Communicator 1.0-alpha6 nightly builds

Note: We would like to support as many distribution specific packages as possible. If you would like to be a maintainer of such a package - please let us know