We've confirmed a few times that yes Grayskull will be back as a non subscription figure in Q4 2010. This was kinda our last shot since in 2011 all the figures will be in the subscription and we didn't want to release him in 2011 as part of the sub when some fans already have him.
Improved Deco and extra accessories. Now that's interesting. I wonder if he'll be the September Bonus figure.