I think it would be a really good thing
Year 4 would be a good time to start learning basic simple stuff, especially since it's mostly logic. They'd have to find some more interesting ways to teach and learn it though.

I learnt some basic coding quite young, thanks to an IT teacher who loved the idea and made us play around with Java and Pearl (he was a Linux obsessive) and I could do basic stuff. Forgotten it all though.
( Amberl was stripey and dominated Europe, Thu 15 Sep 2011, 13:26, 2 replies, latest was 14 years ago)

I think the first classroom computer stuff I played with was Logo, as I mentioned above.
Very simple language and features instant graphical feedback. Teaches most of the basics too - repetition, selection, the idea of combining operations together into units which can be re-used.
(BrianHequator was stretching owls, on, or around, Thu 15 Sep 2011, 13:36, Reply)

Java is horrific when you get further into it.

( Agnostic Antichrist Baltimora, Thu 15 Sep 2011, 14:16, Reply)