I think a great addition to full screen apps would be for one, the ability of course to have more than one if you have multiple displays...I really hope that is fixed....and the other thing that is annoying me is that no other app can exist on top of a full screen app. So if I have a chat open it can not be on top of my browser...that is pointless. I think non-fullscreen apps should be able to occupy the same space as full screen apps. Why make full screen it's own desktop? Why not just work it like every other OS uses full screen? So far this is my only complaint with Lion....oh that and the inability to pin and rearrange desktops in MC....fix those items and it will be a perfect OS!