Snag the typekit js and pop it in the TinyMCE Editor

typekit-editor.js

links = document.head.getElementsByTagName('link');
tkCss = '';
for(l in links){
    li = links[l];
    if( li.rel == 'stylesheet' && li.href.match(/use.typekit.com/) )
        tkCss = li.href;
}
if( tkCss.length ){
    s=document.createElement('link');
    s.setAttribute( 'rel', 'stylesheet' );
    s.setAttribute( 'href', tkCss );
    iframe = document.getElementById('content_ifr');
    doc = iframe.document || iframe.contentDocument || iframe.contentWindow && iframe.contentWindow.document || null;
    doc.head.appendChild( s );
}