The listed changes are all in the presentation side of the app, and cover...
- UI Improvements
- Page and Item Transitions
- Fix for erroneous display of Cyrillic characters
It should be noted that 'Old Reader' is not developed by the team behind the Old Reader service. That team have a documented API and list any app that uses it (that they know of) at their site. So while it's not an official app, it is legitimate, and accessing the same date (through the safeguards put in place by the Old Reader team themselves).
Old Reader for Windows Phone is a free download and you can pick it up from the AAWP App Directory.