OMG: Watch Mariah Carey, Jimmy Fallon, And The Roots Sing 'All I Want For Christmas Is You' (VIDEO)

We are forever grateful for Mariah Carey, The Roots, and Jimmy Fallon singing "All I Want For Christmas Is You." UMMM, do we know whose brilliant idea it was to have Mariah Carey, Jimmy Fallon, and The Roots perform Mariah's classic "All I Want For Christmas Is You" using only CHILDREN'S INSTRUMENTS? We'd like to [...]