re: Did Yahoo's Mayer Slap Social In The Face?
Flexibility should be what is most important to Yahoo, or any organization. If Yahoo is really in crisis mode, and work at home employees are unproductive, then maybe they have to come to the office. But will having everyone in the office foster innovation? Maybe, but we'll have to see.
A flexible work environment, where workers come in 1-2 days a week, could probably achieve the same level of increased interaction, and (maybe) foster innovation. But just having people in the office doesn't mean that innovation will magically happen. And, likely, productivity will suffer.
As it has been stated in other posts, remote workers generally use their "commute" time to do work and are usually more productive. Speaking for myself when I go to the office, my commute of 90 minutes each way shortens my work day on each end. When i work at home, the 3 hours I normally spend commuting is usually given back to the company.