I lost track of a news link I saw that reported this as something akin to Disney starting their own Mouse House digital locker service like UltraViolet. It's not, and thank god, since we've got enough locker up there in the magical, mysterious "cloud".
Having redeemed the Oz the Great and Powerful code, I can say that Digital Copy Plus is just a responsive design site that funnels you to your digital vault of choice, whether iTunes, Amazon, or Vudu.
Who actively uses Vudu, by the way? Other than Walmart employees?
Now, you can redeem those codes directly to your iTunes account from any web-accessible device via the responsive site.
The biggest plus to Disney moving away from disc-tethered Digital Copy (aside from general convenience and stronger engagement) is that their Digital Copy files are now HD and carry iTunes Extras. Paramount, Universal, and Lionsgate/Summit releases have had this since last year.
iTunes Extras still, inexplicably, only work in iTunes itself and not on iPhones, iPads, or the AppleTV. Maybe that's another no-brainer, long-neglected UI problem Apple will fix in this, the year of Apple adding missing features that they should have years ago.
Fox is now the only studio delivering Digital Copy in SD on physical discs.