@pastanaga - I think it's an ongoing process. I know there have been a few that have changed recently. People made it standard syntax to use certain nouns as verbs, for example, like access, which used to just be a noun, but became a verb because it was useful.
People just used it so much that eventually the dictionaries all declared it to be a verb as well as a noun.
They actually put out a list almost every year of what new words and usages of words have been put in and what ones have been left out. Languages are constantly evolving, both words and grammar rules, and English as we know it probably won't exist in a few hundred years.