Monday's New York Times crossword is the handiwork of Tom McCoy, an undergraduate member of the Yale Grammatical Diversity Project. I wouldn't've thought it possible, but he's managed to make a coherent theme out of a nonstandard grammatical variant in American English.
I won't spoil it for people who want to solve it — subscribers to the Times crossword can download it in Across Lite format or as a PDF. But if you don't mind the spoilers, you can read the constructor's notes on the Times's Wordplay blog (Tom gives a nice plug for the YGDP there). And you can see the clues and completed grid on XWord Info.
Bonus: One clue mentions Google Ngrams, surely a first for the Times.
Update: For more, see the Yale Linguistics Department's news page.