I also ran into this problem (TinyMCE not loading in Static Text portlet on Plone 4.3), and created a fork with a fix. It's available at http://dist.sixfeetup.com/public/ as plone.portlet.static version 3.0.1.1
For the record, I had submitted this fix as a PR, but a different PR was accepted instead (the code for it was simpler), and that became version 3.0.2. I have not tested that version, but I suspect 3.0.1.1 will work for you.