That's actually a pretty crude quote he made regarding Microsoft. By no means to I swear loyalty to any one company. Facts are facts, and clichés are well, simply that.
Anyone who's followed all areas of the mobile market segment will know that Microsoft is taking a very, very big gamble with Windows Phone 7... The complete integration of social networking and cloud access into the user interface. This goes far beyond anything any other platform is doing, almost to the point that it's frightening. It's definitely unfamiliar ground for someone like me.
Microsoft Office 2010 is also designed around the concept of cloud computing and being able to access your documents anywhere.
As far as smart phones replacing traditional PCs... that's a pretty ludicrous statement. I think that smart phones will replace traditional PCs only in the sense of how much dependence we have regarding our daily lives. I think as smart phones become more and more powerful, and the market segment follows the path that Microsoft is gambling on (seamless integration of social networking), we will find ourselves doing more and more things on our phones that we used to have to do on our PCs. Why load up my computer to post on twitter/facebook/etc. when I can do it all from my phone? Why print out directions to go somewhere when I can get live directions from my phone? But outright replacement to point of PCs become obsolete is laughable...
The quickest counter-argument is that it's a matter of form factor. We like our blockbuster games that, even with equivalently powerful hardware, simply cannot be experienced in the same way on a phone. We want to not only be able to read news and documents, but create them as well. By the time PCs have become obsolete in one way or another, it will be by something else, not the smart phone as we know it today.