What is 200xs?
Or the 0Xs, is the decade that begins in the year 2000 and ends in the year 2009. The zero refers to the decade and the X refers to an unknown or generalized number or year between 0 and 9.
This term is Used as one way to avoid confusion with the 2000s (Two-Thousands or 2XXXs) which describes the period between 2000 and 2999; and the Twenty-Hundreds (or 20XXs), which describe the period between 2000 and 2099.
The 200Xs will probably be remembered for the musical genres of Crunk and Emo the way the 90s were remembered for Grunge and (the sort of techno music played at) RAVEs; the 80s for New Wave, Hair Bands, and Old School Hip Hop; the 70s for disco and the 60s for Psychadellic.