That's an interesting idea - I've always just assigned the contexts by typing into the context cell for each action, but I can see how it would be handy to be able to do this via drag and drop.
Not currently possible, but I'll file a feature request on this; folks that want to see it added should email the
support ninjas and they can vote this up. Thanks!
Edit: not currently possible in project mode, but yeah, possible in context mode. :-)