Is xfce under development yet ? or its a closed project ?
Its always been under development and is not a closed project. Have a look at the git tree to see what work is being done. Also feel free to view/subscribe to the Xfce-annouce and Xfce4-dev mailing lists.
As of the last week, xfce4-power-manager 1.3 has been released and parole has seen a flurry activity.