Ug, what a stupid change.  Thanks GP for making me take 30 minutes out of my day to hack around this.  For anyone that would like to revert links back to the non-interceptor crap, you can use the following:

Go to control panel->Style & Colors->Advanced Style Settings->Footer

In here, click the < > button for html input.  Add the code below.
Basically what this does is adds a function that undos what the new GP function does.  Anyone that looks at the source can see that GP encodes the link at the very bottom.  Using setTimeout(, 1) will cause our function to be executed 1 millisecond after page load, reverting all the links (since we can't block their encoding of them).  All my wowhead popups and off site links are back to normal.  Yell if there are any questions.

Code to add to footer:

edit: Remove the line breaks around the script command, it would let me post it with those in.

<
script language="Javascript">

function fixStupidLinks()
                  {
                    try
                    {
                        var interceptUrl = '/Outbound.aspx?Destination=';
                       
                        for (iLink=0; iLink < document.links.length; iLink++)
                        {
if( document.links[iLink].href.indexOf( interceptUrl ) != -1 )
{
  document.links[iLink].href = unescape(document.links[iLink].href.substring( document.links[iLink].href.indexOf( interceptUrl ) + interceptUrl.length)) ;

}

if( document.links[iLink].href.indexOf( "javascript:" ) == 0 )
{
document.links[iLink].target = "_self";
}
                        }
                    }
                    catch (linkExc)
                    {}
                  }
                  setTimeout("fixStupidLinks();", 1);

</script>

Just a bump in case someone already copied my code above, I added a check for the broken mail problem too.  It was changing the Tree View of Select From Guild Members to be an external link.  It should now catch that and set it back to opening in self.

Does this stuff get tested at all or are we just paying to be beta testers?

It works for me too.

Have you noticed that they've made their interceptor a little dynamic? If you make a wowhead link now, it says:

Im not too smart...what am i supposed to be removing out of that code for it to work?  Thanks!

Thanks!  got it!