This is a very exiting news, although is has about a week now after releasing, we have been testing it in several devices before making our own mind. The result is that this is the most easy Jailbreak process we saw since jailbreakme.com (for iOS 4.2.1). And it works just fine!
You just need to download Evasi0n form here and run it. It will ask you to connect your device (by cable) and do it all alone (except for a couple o times you need to slide your unlock bar) and there it is, you got Cydia! :)
From Cydia, you can download many, many useful apps and settings that are not allowed in the Apple Store. Download Themes, ringtones and many other features like Furiousmod (used to bypass the 112 dialing in the Gevey Ultra), and many other hacks. One of my favorites is Cyntact from Jay Freeman that allows you to add pictures to your contact list and the 5 Icon Dock that, like its name, lets you have 5 icons on your dock.