For everyone rejoicing in this thread, there’s no way Apple will allow this outside the EU. From the article:

We also found references to a region lock in this API, which suggests that Apple could restrict it to specific countries. This wouldn’t make sense for MDM solutions, but it does make sense for enabling sideloading in particular countries only when required by authorities – such as in the European Union.

I want side loading as much as the next guy, but Apple will only do the bare minimum to appease the EU regulations. Suck for those of us outside the EU.