I'd like to provide a different perspective. This is anecdotal, but I have "before and after" experiences that directly relate to the topic.

I work as a Presales Engineer for a software company. At the beginning of this year, we switched from a 90s-style cubicle setup with dividers to an open-office setup. When the change was announced last Fall, everyone on my team voiced heavy skepticism. We thought that it would greatly reduce our productivity as well as the already-limited privacy we had in an office setting. We had systems in place to limit the interruptions coming from the sales and marketing teams, and an open-office plan would practically nullify them. But we were the minority, so our concerns were swept under the rug. Fortunately, things ended up well.

For the sales and marketing folks, things have improved greatly since we made the switch six months ago. They now sit with us in the same "pods," which are collections of IKEA desks. Each pod has several sales and marketing people and one or two Presales Engineers. They can ask us any question at any time. And unlike with email, which we could previously put on a queue to answer later, or instant message, which we could ignore or temporarily block (DND mode), we now have to provide the answer right away. They can in turn relay that answer to the sales channel or the customer with a much shorter turnaround, which helps to advance and close sales faster.

As for us Presales Engineers, I cannot tell if the net result has been a positive or a negative. On the one hand, we now have a lot more distractions. We see people walking around and we hear their conversations. I personally have memorized the phone scripts that my pod-mates use when they call customers. Another negative has been team cohesion. In the previous setup, my team used to sit together on one side of the floor and we could have conversations much more easily. Now we're spread out all over the place, and most of our interaction occurs via group chat (Google Hangout).

Collectively, everyone's morale has improved quite a bit. It's very refreshing to be able to walk out of the elevator into an open space, as opposed to a claustrophobic, never-ending group of cubicles. And all the pods are right in front of the windows, which means everyone can now enjoy the Southern California sun and the great view of mountains we have from our office. I purchased a nice set of noise-canceling headphones (company paid for it) that I put on whenever I need to get in "the zone" to work on things that need deep concentration, and I trained my pod-mates to not interrupt me when I have them on. It works really well. Other pods have also come up with systems that work for them.

Another collective benefit has been social cohesion. When the teams were separate last year, there was an "us vs. them" mentality. The sales folks saw us engineers as unapproachable, and we saw the sales folks as needy and disruptive. Now though, each pod has become a team, and people are much more willing to help each other and collaborate. This has eliminated a lot of the tension in the office.

It is worth noting that the above occurred within the context of a sales team and the engineers that support that team. That said, I'm pretty sure it can also apply to developers. We actually had one of the developer teams move to our floor a couple of months ago (the A/C unit on their floor broke). At first they had the same fears as my team of engineers had. But it ended up working out really well. Sales people never interrupt them, and communication flows from sales to Presales (my team), and from there to this group of developers. Being able to walk over to their desks to show the problem we're having and walking through it in person, as opposed to trying to do it over email or IM, has been a great boon for both parties.

Bottom line: open-offices have their pros and cons. The vast majority of Hacker News users are technical people and it seems most of them are adamantly against open-office plans. But as someone who has a bigger picture view (since I work with everyone in the company), I can tell you that there is a chance the net result can be a positive if the plan is implemented well.