The Telegraph has noticed that Google recently started testing black links, giving the page a certain This is Spinal Tap (or maybe goth) flair. There doesn't appear to be a clear pattern that determines who gets picked, but some test subjects have reported that the links revert to blue when you log out of your Google account and sign back in.
Google has declined to comment so far (we've asked for a statement regardless). However, as with most such experiments, it's safe to say that those black links aren't guaranteed to reach everyone. Their fate likely depends on both raw test data and public feedback. The links may get the A-OK if Google sees more people clicking results, or fade into oblivion if there's enough of a public outcry. One thing's for sure: the very fact that this is even an issue shows just how much people take Google's design for granted.