Look of the Day: Nicole Richie in Herve Leger

Not only did Nicole Richie look stunning as she attended last night's taping of The Late Show, but she also announced her engagement! Nicole, who arrived in a figure hugging Herve Leger "Alexis" dress and House of Harlow gladiators, broke the news of her impending nuptuals to Joel Madden to Letterman, showing off her mammoth rock of an engagement ring. Joel also confirmed the news on his Twitter