You're assuming the board knew any better. For all you know, Ballmer fought against it. They could have been screaming at him to get into phones and he found a solution. Full disclosure I revel in the demise of MS.
Can we do more than 10 per page? I hate having to click next, next, next in between scrolling. If I could just flick the scroll wheel and let my eyes pick out the ones I like it would be so much easier!
Seriously, who instigates these fads? It's like every year there's some new business model that everyone follows like a bunch of lemmings. Last year (or the year before?) it was everyone working in the office (as opposed to at home) because someone at Yahoo! decreed that was the way to go.
If it isn't obvious, announcements like these are purely PR. Once the general public starts reading the stories like "Facebook is agile and uses open offices", they begin to associate the experience of their Facebook iPhone app with the result using agile and open offices. They then ask their boss why their CRUD accounting/finance/analytics app can't look and feel like FB and then those bosses (the CRUD vendor clients) put pressure on their vendors (such as IBM) to change or they're going elsewhere.