Merriam-Webster had a contest and the word of the year, as voted by you, was w00t. While it’s not in their official dictionary, it is in their open dictionary online and have suggested that by winning, it may have a better chance of entering their main dictionary.
I’ve said it before and I’ll say it again, I’m not sure about some of the terms that are entering our dictionaries. In recent years, we’ve seen a lot of slang entry regular dictionaries. While there use has certainly increased, I’m not sold that it’s enough for a proper dictionary – definitely a slang dictionary.