This article was tweeted by Cyanogen who is responsible for for creating an Android rom from scratch for several devices. I tend to believe him, the guy writing the article, and Google themselves.
http://thedroidguy.blogspot.com/2010...r-hurting.html
That being said, there are some poorly written apps out there that can keep your phone from sleeping. Facebook 1.3 had a bug that caused this and they fixed it in 1.3.1. If you are getting less than 12 hours of battery life on average usage, you should look into what apps are causing partial wake time.