I stopped by the Overdrive booth at the National Book Festival yesterday and the Overdrive folks were kind enough to show me their new app. I couldn't shoot a video, unfortunately, because the app is still in private beta. But they are still on schedule to be released this year, with Android coming first and iPhone, iPad coming later. And yes, the iPad will be getting its own app.
The new apps will support both ebooks and MP3 audiobooks checked out of your local library (they're going to replace the existing Overdrive Media Console). I'm glad OMC is being replaced, actually; it was not a good experience.
They showed me the Android app (almost everyone in the booth had it on their Android smartphone). It has a decent set of ebook options: 7 font sizes, several font types, brightness, and a night reading mode. There was also a CSS option that I didn't quite understand. It looked like you could uncheck a box and ignore the CSS in the ebook.
That last one could be interesting; it's one step away from letting the user control all formatting.