Interesting article. But right now I'd say this one study is very much in the minority and actually the fact that it doesn't have to be water has become more and more accepted for a while now, that part is not new.
"The human body cannot store water; therefore, fluid mustbe replaced and kept in balance daily. Body water turnoverrate is estimated to be 4% of total body weight to maintainnormal body functions, which include excretion of bodywaste and evaporation from the lungs and skin..."
It seems the media, as usual, has latched onto something and blown it out of proportion. 8 glasses is a general recommendation and is certainly adjustable based on your lifestyle and other factors, but it appears to be a good generalization.