Having worked as researcher/dev in both private office and open space setup, I am absolutely convinced that private offices are way more productive than open office setup for researchers and developers. Most, if not all, of my colleagues feel the same. In fact, I don't think I will ever accept an offer from a mature company (not startup) which houses its developers in open space.
The trend in most modern workspaces is to have mixed use. Generally open plan for most day-to-day work and then a variety of private areas. For example offices and cubicles that are shared. Development is always tricky because often you need clear air to solve problems but then occasionally collaboration is required.
It's not really that tricky- there are many tools for collaboration including IRC. And you can always go to another developers office, in the ideal one developer-per office situation.