It's something different that has yet to be implemented, to my understanding. The digital downloads you see are the standard retail releases, just in digital format.

The "upgrade" downloads are designed for 1.0 account holders who want to upgrade their existing accounts to "collectors edition" to snag the CE bling that comes with the package. I think it's $19.99 (price should be on the site). Remember that all 1.0 account holders technically receive ARR for free, since we already purchased the original 1.0. So you're basically paying 20 bucks to get CE status and the bling that comes with it.

Hope this clears up some of those questions for ya.