I think cell phones are going to evolve into handheld computers, and for simplicity, phone calls and text messages are going to be just plain old network applications. At that point, people will probably be able to install the OS of their choice, and load protocol compatible software of their choice. We just need to wait.

I think the current proprietary software is a reflection of the greed of software developers( trying to create a licensable programming monopoly for their product) and limitations of the current systems( not enough ram and miniaturization yet).

But the competition is becoming ruthless, and that will mean the people who adopt open source, will eventually win out, because it is cheaper.

I can't wait..... I know I could do what the IPhone does with Perl/Tk or Perl/Gtk2. OpenCellPhones

The next step, will be similar to what happened when phone network access was opened ( by a lawsuit), by companies who provided discount service. The bell weather will be lawsuits forcing AT&T and Verizon to open up to any compatible software that works on the cell systems.