It's just that: it's a system. If a Google user decides they want to withdraw from all our services and they want to take the information they've shared with us, we're building a mechanism so that product by product, with one simple button, they can not only pull that information out of our systems, they can send us a signal they want that deleted. We'll provide it to them in a format that they can then use in an alternative system. That doesn't necessarily mean service to service, but it means we won't give them some unintelligible electronic file that they can't analyze.
The goal really is to keep us honest and to provide our users with a tool that allows them to make that clear decision about whether or not we're providing value and usefulness to them on a daily basis.