Be clear on this: if you're not a jailbreak app developer then the redsn0w 0.9.5 beta release is not for you. The iPhone OS 4 jailbreak previously hinted at
is for real and it's for devs only so that they can prep their wares for the summer update. Don't worry, it doesn't reveal anything new to Apple and no, it won't work on the iPad -- it's Mac OSX only, iPhone 3G only, and iPhone 4.0 beta 1 only for now. But hey, it's early days, at least you know it's out there and that people smarter than you are tending to things.