I was thinking of getting cm10 too, but I wanted to wait for a stable release. Coming from iphone which I have always jailbroken, I nevertheless still feel a bit insecure about rooting. I was quite comfortable with the jailbreak process, but now looking at how to root, I feel like I don't know enough about the whole procedure, like recovery etc. I admit that iphone felt easy to go back to stock, simply plugging it into iTunes to go through backup and restore. Reading about bricked devices and warranty loss due to root doesn't make it attractive to me.. I love my S3 and I don't want to hurt it ;-)
From what I've read so far you need to have Cm9 to be able to flash cm10?
I guess I'll stick to the official stuff first until I know more about the whole root and flash procedures, or at least until I read an article on how superior cm10 is in comparison to touchwiz.
Sent from my stock GT - I9300 from Luxembourg, Europe using Android Central Forums