This WSJ article makes the case that you can probably get by with less than eight. Given the audience of the Wall Street Journal, I am not surprised they would have such an article.
For more reasonable people, this article in Real Simple (So Now We Only Need 7 Hours of Sleep? Not So Fast) makes more sense.
As I get older I lean towards getting more sleep, but to each their own.
Regardless, the weekend is coming up. Get some sleep.
P.S. The image, from the wikipedia section on sleep, shows the downside of lack of sleep.