when for LINUX ??

There's no official word there will be a linux editor or standalone player, but they have mentioned they'll make a linux compatible molehill based webplayer, no word on when that'll be done though

Unity 4 and up support publishing to Linux(specifically Ubuntu as of this writing).

Unity Technologies still do not provide a Unity Web Player for Linux browsers. I also haven't heard any plans on doing so.

Workaround:

Previously Linux users tried to install Windows versions of internet browsers to run the Unity Web Player using Wine.

The Pipelight project has made a plugin for native Linux browsers. It still uses Wine, but at least you won't deal with Windows versions of internet browsers. See the community set up wiki page - http://wiki.unity3d.com/index.php/Running_Unity_Web_Player_on_Linux_using_Pipelight