There are a few big tree enhancements that have gone into SVN and will be in the 1.3 release. (You can see them in the nightlies now.)
1) Drop between
This lets you specify the ordering of nodes when dragging and dropping. You can also use it to reorder the nodes in a tree. Although the feature/parameter is called dropBetween, what it actually lets you do is drop the drag-node either "before" or "after" the target TreeNode, to become it's sibling, rather than onto the target TreeNode, to become it's child.
