Is it possible to use multibinding in WF (with ActivityBind)?

I would like to bind multiple dependency properties of other activites开发者_开发技巧 to a dependency property (of type object[]) in my custom activity. Is it possible to define this multibinding :

• In the workflow markup (probably somehow combining multiple ActivityBind's)
• Set up the property editor in such a way that I can even edit this binding in the workflow designer ?