It's a rare move from General Mills, as food companies have been wary of GM labeling because they fear it would cause consumers to think that such foods are dangerous.
Indeed, General Mills went out of its way to say that the Cheerios change had nothing to do with safety or pressure from anti-GM activists. Tellingly, though, the company said that the alteration was due to demand from customers - who presumably are concerned about safety.
The question now is whether other food companies will follow suit and what the long-term effect on GM companies such as Monsanto (MON) might be.
General Mills blog post.