I've prepared new layout of Tree component. You can see it here: https://jira.jboss.org/jira/secure/attachment/12330348/tree.zip
Current layout is based on DIV's. Besides I added to layout a possibility to set a tree width. If the tree width is smaller than width of tree items then we cut part of tree item content. For seeing of hidden part of content I propose to use tree hint (now commented in code). If we don't need this functionality (I say about hints) I can make Tree code more simply.
But in my opinion the tree width is very needed parameter for making of UI and I propose to release it in any case