BFR seems to have great potential as others have mentioned it liberate my Adobe DRM'd books for use on the iPad which is much more of a productive environment for me. I do research much more than recreational reading so I have some particular priorities. I'd very much like to see BFR evolve into a total reading and research solution.
The top new features I would vote for are:
1) ability to organize the library into shelves or folder or whatever metaphor - iBooks and Kindle don't have anything useful here but both Goodreader and iAnnotate have credible approaches to organizing large libraries (100s to 1000s of titles) Simply sorting by title or author or categories that might have been assigned by the publisher is not sufficient in a large library
2) less cumbersome highlighting - highlighting shouldn't imply a note and a bookmark