Rooting still voids the warranty. Basically all this law says is they can't take you to court or fine you for doing what you want to your device (though they can make it as hard/easy as they please)
And Paul, rooting does void your warranty. Because if anything goes wrong with your device, even if the root didn't cause it, the carrier or handset maker will say it was your actions (aka user error) that caused the issue and they'll use rooting as the cause.
And screen cracks arn't covered by warranty, that would be insurance, which should (unless asurion is stupid) cover rooting just as much as it covers dropping your phone in the pool