Q:

emberjs dynamic routing, serialize giving Uncaught TypeError: Cannot call method 'get' of undefined

Why is an error thrown inside the serialize function line id = context.get('id'); 
Specifically why is it even attempting to run the serialize when I load the index route.
full demo: http://jsfiddle.net/mh8Xu/1/
   serialize: function(router, context) {
                    var rtnVal = {},
                        id = context.get('id');
                    if (context) {
                        rtnVal = {post_id: id};
                    }

                    return rtnVal;
                }

A:

The error is in {{action goToShowPost context="post" href="false"}}.
I believed it was backward compatible, but seems it's not.
Now you have to directly pass the context, like this: 
{{action goToShowPost post href="false"}}

