I run the digital preservation efforts at a respected museum of photography and film, yet my comments are my own, not theirs.
Frankly your assertion is a bit myopic.
Digital media provides a key benefit that mitigates the volatility extensively, namely, mathematically provable exact duplicate copies, something you simple cannot do with film transfers, regardless of quality of your equipment. You think the government settled on microfilm because if the world ends and life re-evolves we can hope they'll read it easier? That's a stretch.
Plus, I'll take needing to swap a hard drive for vinegar syndrome (which should be rearing its head in the next decades for all the non-polyester microfilm stock) any day of the week..
Right now, we can do 4K transfers easily (read: at many different labs).. and a feature length film is, oh, lets just call it 15TB for arguments sake.. a big hefty chunk.. in 2011. In the next decade, prices should come down to make this 'affordable' to archives, especially with respect to LTO tape libraries, as they can further help mitigate bit rot (by tape rotation) and obsolescence (Oracles support for "any tape any slot" kind of stuff helps out).
With cinema being on the brink of a digital turn, digital will soon become an artifice (replacing the projection print).. if we printed it to film, we'd have quality loss from the originals.
Considering we're beginning the transition in the field, it means archives need to start DOING this stuff, to gain competency for when we have no choice but to do it.
Will there be missteps? There already have been (ask any museum of reasonable size about laser disc).
The big shift for activists is that digital preservation isn't a function of archive management and library science, but of information technology.. will they inform IT WRT requirements? Certainly. But IT folks have been tasked with persisting digital data since approximately day 1 of the profession.
There are plenty of nay-sayers, and I feel strongly that said nay-sayers are damaging the ability of institutions to deal with digital, because we WILL have to, so we might as well start now with challenge pieces and advancing standard conservation practices to incorporate digital.