Not quite yet; but it is possible to show/hide menu items (as shown in our toolbar sample). With this you can gain pretty much the same functionality, with the big difference that you need to design your menus carefully from the start--basically the menu should contain all possible items, and later you can hide some, depending on the context.

It is true though that we still have work to do concerning the "dynamic aspect"; on the other hand, of all Web-based menu systems, we believe ours is the most "dynamic". ;-)