Sounds like the Zombie talent isn't seeing enough use at Larian HQ...
Given Larian's intent to offer long-term support (and presumably lots more patches), a beta series of patches as others have suggested ("use at your own risk, not fully tested, etc") may be the best way of squaring the circle and keeping most people here happy.
Take a page from the Infinity Engine games and add an Override folder which is then used as the first source for any data files. Beta patches can be implemented as zip files that go into Override (allowing for compatibility with Steam and GOG releases) and "official" patches then only need to clear that folder to "de-beta" an install.
