ARS Technica says the 2007 "word of the year" is w00t:
Yes, 2007's word of the year is "w00t," an expression so likely to die off in the near future that I can just about see its pallbearers lining up down the hall. Merriam-Webster offers this definition for those not quite l33t enough to spend their lives in online chatrooms: "expressing joy; similar in use to the word yay."
The word is not even included in the print version of the dictionary ("yet"), but that didn't stop voters from flooding the tubes with ballots. Perhaps they were interested only in seeing what sort of unintentional hilarity would result when the wordsmiths at Merriam-Webster tried to explain the genesis of w00t to the world at large. If so, their wishes were granted.
"This year's winning word first became popular in competitive online gaming forums as part of what is known as l33t ('leet,' or 'elite') speak-an esoteric computer hacker language in which numbers and symbols are put together to look like letters," said the company. "Although the double 'o' in the word is usually represented by double zeroes, the exclamation is also known to be an acronym for 'we owned the other team'—again stemming from the gaming community."