Rather than repeat what's already been said on this fascinating subject, please check out Mobile - Facebook and Google Can't Live With It and They Can't Live Without It by Keith Teare. In this article he also includes several links to his other recent articles on the topic (great pieces each).
And last week in Forbes, there was Here's Why Google and Facebook Might Completely Disappear in the Next 5 Years. Now, personally, I believe both will ultimately survive. However, I also believe that both will look very differently than they do today. Two companies built on the assumption of the web will have to become two companies prepared to blow up those assumptions. Again, I think they will succeed here. Their people are too smart not to.
What about you? How do you see your business addressing this change in consumer behavior away from personal computing and toward mobile devices? Will it affect you in any way? If so, how? Please leave your thoughts by clicking the comment link below.