I was very happy to read Marc Osofsky's very well reasoned and well written article about setting content free. In the early days at a company that I used to work at ;) we had a simmering debate about whether or not to require registrations to gain access to our white papers. As you might expect, the consultants (who joined the company because they got the concepts behind open source software and Web 2.0 and also wrote the white papers) wanted to make the white papers freely available. The sales organization, whose business process centered around processing leads, couldn't see the logic of not getting contact information whenever possible. For a long time the company had a required registration and our sales guys made qualification calls to "Superman" and "Mickey Mouse." Hey, a lead is a lead. Right? Actually, the sales guys did get frustrated as you can tell from this blog post.
Web 1.0 expanded markets by allowing traditional business models and practices to be less geographically constrained. With Web 2.0, communication has surpassed the point where it can be directly and centrally controlled. By producing good content, companies are able to extend their reach beyond the realm that they can actively participate in. People download things, try them out, blog about them, and talk about them in public and internal forums (physical and digital). If they like what you have to say and have problem that you can solve, they will find you. Maybe 1 in 10,000 contact you. That is pretty good if you are reaching millions. Furthermore, the 1 person that calls has already spent a lot of time pre-qualifying himself saving you a lot of work. A great example is all the companies that put their product videos on YouTube. I am seeing more software companies making their documentation available but there is a concern that their competitors will have access (as if they don't already).
All this doesn't mean that you can forget all of your traditional prospecting work. That is, unless you have an amazing product that just sells itself. You need to keep a balance. Keep your sales guys getting their leads and working on them. Just don't constrain the power of your published information by controlling it with a pre-web mindset.