Olive tree's reader is decent already and they have a lot more translations available today (like NIV and NASB). The thing that I like the most about the Olive Tree reader is that it supports multiple fonts, including a smaller font than default that allows a lot more information on the screen vs what Beiks' has.
Their developers are really nice too. I sent them some feedback and they actually wrote back and sent me a beta version with some fixes for what I was complaining about!
I also suspect that other features like bookmarks and a better verse selector will show up in the Olive Tree reader shortly