You are absolutely correct it is there. However, I noticed that on the main page the 4s is shown, no beta is shown. When you go to the 4s page, no beta is mentioned. Just on the Siri page.
As another person mentioned, there is a whole lot of people that don't know what a beta is.
I guess Apple could have used that when the iPhone 4 had the supposed antenna issues. The antenna is still in beta, so don't worry....
Yup! The battery problems that Apple acknowledges are due to the fact Siri is in beta too. The static/echo problems? Not Apple's fault. They released a beta program on the phone. Buyer's should have expected to have all of these issues because Apple clearly used the word "beta"....somewhere...at some time..