Didn't sun "open source" sparc? Doesn't ARM succeed partly because their licensing is more "open"? Now that the necessary software is mostly open I wouldn't be surprised to see people moving down the stack into firmware and hardware.
I'm sure that you know this, but "open" and "patented" are not mutually exclusive. Lots of codecs are "open source" but you can't use them commercially without paying money to someone (e.g. MPEG-LA).