Remember the flap when the State of Massachusetts decided that all State documents had to be in Open Document Format or PDF so that anyone could read them without obtaining any special software? Well, it is not over at all. France, Denmark, Belgium and some US States have gone that way. The EU looks set to dictate that, as well, though it might take a while.
James Love's blog entry on the subject is the single shortest and most lucid on the subject I have seen and I thought you might wish to read it.