My soon to be 8 year old is enjoying Scratch immensely. (As am I.)
Without any instruction, apart from two tutorials from YouTube, he has made a number of exploratory programs.
I cannot recommend it more highly then seeing him dancing in delight as he showed his mother how the flying bit of doodle (made with the in-skin paint widget) that shoots from the mouth of the cat makes the stick men 'ghost'.
He set up broadcasts, loops, events, and keyboard control, all on his own.