GCE recently received certification from Apple and started shipping PCBs for iPods in small quantities, the sources said. The shipments are expected to significantly increase next year, the sources added. GCE declined to comment.
The more individual manufacturers you have, the less likely you are to run out of components. More manufacturers also potentially means lower production costs, but it also brings the potential for more flaws to slip through the cracks. Since Apple tries to pride themselves on quality, they'd better hope they aren't spreading themselves too thin.