I believe it has something to do with certain publishers not willing to offer their translations to open source software. eSword is NOT open source, but is free. MacSword/CrossWire is open source & the only proper response I have heard from Zondervan (for eg) is that they don't work with open source software. If they were to change their stance on that, then I believe that things could progress. :)
But, please feel free to contact publishers on our behalf. I made up a list of publishers to contact in January (2010) but have been too busy with PocketSword and with other things in my life to have had the opportunity to contact them. :(