The good news is the developer was nice enough to provide a change log (see below) detailing the main changes,
5/1/2013 – Support for new syncing services will be added before GR shutdown.
What’s new in v4.5
New: Secure Oauth2 login.
New: Faster sync engine (supports incremental syncing).
Updated share menu design with copy title and link options.
Updated ‘headline + large images’ list style
Fixed: Syncing issues or errors
Fixed: Live tile / background task issues.
Fixed: .Mark above as read. bug.
Fixed: Configuring Facebook or Twitter accounts.
Several other bug fixes and performance improvements
After playing with the post updated app we are happy to say that sync speed does appear improved and we love the “headline + large images” list view which gives a fresh appearance to the app.
The other important point to note from the update change log is that the developer re-iterates what he has stated in other forums, in that the app will live on after the end of Google Reader by utilising added support for other RSS syncing services.