Sadly, "ain't" is among them

While this may not be of too much interest to very many of you, as a lover of words, I'm kinda tingly knowing that there are now, officially, 1 billion words documented in the English language. By documented, I mean that they are recognized by the Oxford English Corpus, the press that prints the dictionary under the same name.
The Corpus draws on weblogs (maybe even THIS one!), newspapers, magazines, chatrooms and fiction for the new words that may end up in the most-recent edition of the dictionary. Lexicographer Catherine Soanes said the database is not [really] a collection of 1 billion different words, but of sentences and other examples of the usage and spelling. In the most recent edition of the dictionary, August 2005, the Corpus added words such as "supersize," "wiki" and "retail politics."
Launched in January 2000, the Corpus is part of the world's largest-funded language research project, costing $90,000 to $107,000 per year. The Corpus collects evidence from all the places where English is spoken, whether from North America, Britain, the Caribbean, Australia or India, to reflect the most current and common usage of the English language.