@epaulson: you can take some comfort from the experience of the open source software world.
There have been forks of high profile projects. Lucid Emacs broke away from GNU Emacs, for example. They had good reason to do so, because GNU Emacs had become rather moribund. The fork was perhaps what prodded the GNU Emacs team back into action, and there was a happy ending because the forks later merged. If that fork hadn't happened, GNU Emacs would have been in a weaker position today.
Much the same happened with the GCC compiler. It had become rather moribund, and the EGCS team forked it. (EGCS stood for Extended Gnu Compiler Suite or something like that). The fork prodded the GCC team back into action, and there was a happy ending because the forks later merged. If that fork hadn't happened, GCC would have been in a weaker position today.
Modern projects like Firefox get forked all the time. Some forks are experimental, some are due to a difference in philosophy, some are failed attempts to "get something for nothing". Some of the forks die out, some of them get merged back into the mainstream, and some (like IceWeasel) happily co-exist in a symbiotic relationship. The possibility to fork doesn't hurt Firefox.
So what if someone wants to fork Bitcoin? All that really matters is that those who don't want to fork can continue to use the unforked version.
Of course there will be disagreements in the future, but they're not going to be helped by any kind of legal framework. As kiba says, everyone except the lawyers would lose from that.
I expect that as long as Satoshi is around, the version that he blesses will remain dominant. Human nature is like that.