This may be looking too far ahead, but I am wondering if it would be worth it to partner with one of the older companies that make Bible software for other platforms. For instance, Laridian currently partners with BEIKS to offer their content to the BlackBerry platform. They also announced today that they are partnering with Bits of God Software to make their library available on the Palm Pre.

If a Qt-based Bible reader would have access to a library the size of what Laridian or Olive Tree have to offer, it would be really good. I am not sure how open source you could still keep it though if this path was chosen.