I don't think this is currently possible, if it is I'd love to know how, but if not I'd like to suggest it.
Currently I can only assign text, a boolean or an integer to an object. Could it be an option that we can assign other objects to an object in a similar way?
I think it would be easier to say have an array attached to a sprite which could hold inventory data or something like that, than to have a global array. Sure the global array method works if you've only got one player, but using such a method in conjunction with say the multiplayer object can start to make the array a bit more confusing, especially for beginners. If the array could be set as a child of the sprite and each sprite had their own array, referenced like a behaviour can be would make construct easier to work with in my opinion.
Another use could be to have a sprite as a child of another sprite which could function like a container, where if the parent is destroyed all children are subsequently destroyed, but if a child is destroyed its parents and sisters are not destroyed. Again, I think this extra aspect could make construct a lot more intuitive than it currently is.