BMW is trying to feminize their brand a bit, and from a marketing perspective, it makes sense. BMW has the stereotype for being a 'guys' car. Adding an emotional term like 'joy' appeals more to the masses of all backgrounds. Please remember these ads are being aired for the 2010 Olympics viewer, which means, families, and not an ad in between a NBA or football game.
'10 E92 Monaco Blue 335i / Gray Dakota Leather / Steptronic / Sport / Premium / Navi / L7 / 18" Performance Wheels / HPFP fail @ 8400 miles (replaced with #933 pump)