First of all, I would be deeply thankful if someone could post a screenshot of the current Astral Form (Moonkin Form with the Glyph of Stars).
From what I've found now it looks like nothing more then yourself faded and some stars above your head falling down. This might be a placeholder altho' (I wish it is).
I expect it to look like it does on the spell icon, something like Algalon the Observer ( http://images.wikia.com/wowwiki/images/8/86/Algalon.jpg )
Would be awesome :) Please post your opinions.