Yes, this case law is emerging. Here is a recent article about a newspaper suing over
someone linking to their site.
in reply to Re: Re: (OT) Who can use freely available material?
in thread (OT) Who can use freely available material?
Also according to Wired, Tickets.com won the case against Ticketmaster with the judge ruling "Hyperlinking does not itself involve a violation of the Copyright Act. There is no deception in what is happening. This is analogous to using a library's card index to get reference to particular items, albeit faster and more efficiently."