I don't really think that programming is something that ever kid needs to learn. IT fundamentals certainly, but I am not sure programming is something that is a necessity in life. If it is just an optional subject then that is different.
I was going to say that years down the line it might impact on the ability to get programming jobs as everyone will "know" how to programme. Upon reflection I don't think this will be the case though. People need to enjoy a subject to choose it as their vocation. Being taught something at school doesn’t equate to people wanting to make it their profession. Compulsory (if it is) exposure to programming at school at such an early age might captivate people whom might not be exposed to it otherwise. So the number of programmers might increase slightly but I doubt the numbers would be noticeable in the job market.
As for quality; it will only be as good as the teaching resources that are put together. At the moment the quality of different teaching institutes vary so much. I don't think it will have a noticeable impact on the overall quality of new programmers. I could be wrong though :)