Is NoesisGUI still supported for Unity3D?

Yes. And it's constantly improving and evolving.
There is an Unity package of latest NoesisGUI version - http://www.noesisengine.com/developers/downloads.php
Also licensing has been changed recently http://www.noesisengine.com/licensing.php it's free for indies (< €100K gross annual revenue).

As ai_enabled indicated, 100% supported.

May I ask you what made you think the opposite? (just to improve the visibility of the product).

Thanks!