"Official" news usually comes from here.
Dev-Team Blog
I have jailbroken my iPhone 4 on iOS 5.0.1 but as far as I know there is no jailbreak for A5 devices as of yet as the exploit used to load the jailbreak doesn’t exist on those devices.
Whatever site you pointed to also seemed to be full of questionable javascript ads so I would question it's authenticity.
Jailbreaking is reversible but the iPhone does know that you jailbroke. I'm sure it sends that you jailbroke back through iTunes as well. That being said - you can just do a restore from an official ipsw and the jailbreak will be gone.
Anyway - I tend not to do anything until I see it released on the iphone blog I pointed to up top.
It isn't worth it to everyone and if you are waiting for a A5 jailbreak then many of the things that make it worth it - you already have. For example there is a camera app that makes the camera come up quickly with an iPhone 4 - that already is built in on the 4s. It just fixes some annoyances I have with the default iOS.
-You can have unlimited apps on unlimited pages inside folders
-You can have 5 icons on the dock and launcher bar
-You can access all toggles on your phone with a gesture from anywhere
-you can make your lockscreen useful
Anyway - I think the site you pointed to is bogus IMHO.