Even the pro versions of Eagle are pretty cheap, if you're already using it to make money. It pays for itself almost instantly. Worst case is that you have to keep using an old version of Eagle, or learn/buy a different package.
People think going open source means they aren't at the whim of a company's decisions. Yet I see open source packages getting abandoned more than commercial software. Isn't WinAVR dead at the moment?
Having the source to gEDA would mean nothing to me. I only have time to design PCBs, not write and maintain the software to design PCBs.