I think http://m5.paperblog.com/i/40/406506/new-elder-scrolls-online-video-details-the-st-L-6iTdbp.jpeg is medallion worthy, I'd have loved it in the collectors edition but I think I'd buy it as a separate thing in the store. High quality material and resolution, nicely embossed, no text of course . What do you think?

Nice! Is that fan made or official art?

I think a medallion of just the ESO logo would be better, rather than the characters on one, that's just my preference though.
What would also be sweet is a unique medallion for each alliance.