After talking w/ Yehuda, we came up with the idea of allowing people to provide default actions on triggered events.   

I discuss it a little on JMVC's forum.

http://groups.google.com/group/javascriptmvc/browse_thread/thread/4d5ae9c61f3817f0

But here's what it looks like essentially:

//imagine some plugin wanting to provide default functionality on a "hide" event.

$(".tab").bind("hide", function(ev){ 
          var el = this; 
          ev.addDefault(function(){ 
                  $(el).hide() 
          }) 
 }) 

And allow you to do something like: 

$(".tab").bind("hide", function(ev){ 
   if(!CURRENT_TAB_COMPLETE) ev.preventDefault();