I'm at Microsoft right now. Microsoft has a policy that everyone gets their own office, if they want it. They "if they want it" part there is key - myself and everyone else on my team was given the choice to have either an open work environment or an office environment. Most of my team and I chose to pursue the open route (a lot of our team is composed of designers, not programmers). I've enjoyed it quite a bit for meetings and other collaborative efforts. When I need to get a lot of my own work done though, I escape somewhere else or do it from home. The reverse is true as well - I know some people who chose to have offices who will work a couple days a week out in the open, simply to collaborate with others more closely.

Each has its benefits. Open-plan offices shouldn't die, but people need to realize that they come with ups and downs.