It seems like old news, but Turpial 2.0 alpha 1 is available in de turpial-devel ppa for quantal only. It comes with many features and a new approach. The core libreary is a python wrapper that provides support for identi.ca and twitter, it is called libturpial. It is ideal if you like python and you need a library for playing with microblogging APIs.
The new interface provides more flexibility as it uses webkit wrapped in a gtk frame. It also provides integration with unity. It needs more Message Menu integration. but the future looks pretty bright, as Turpial 3.0 will take what is learned with the WebKit features and start developing native solutions to all the platforms it reaches.
Turpial has gathered forces and now is looking to take over the world, Please do help in making this happen if you have love for the little oriole that can certainly be big.
I personally think Turpial is still lightweight but needs more polish and testing, bugs are welcome. If you install this version, join the mailing list for support.
Keep an eye out for more updates soon.