There is a very interesting blog post on Newsweek by Daniel Lyons, titled Google Wave. Huh. What Is It Good For?, in which he compares Google vs. Apple. The article is about Google Wave, but in it he makes excellent points citing the fundamental difference in philosophy between Google and Apple:
"... Google represents the antithesis of Apple. With Apple, it's all about simplicity. I once joked that at Apple they don't start with the product, they start with the advertisements. If they can't think up a good ad—if they can't tell you, in a few words, what this product does and why you simply must have it—they probably won't bother making the product.""... Apple is a marketing company that happens to do some engineering. Google is an engineering company that has no clue about marketing. Apple is all about top-down control, while Google is built around the notion of open-source software, where you put your ideas out into the world and let others hack away at them, adding to them and changing them."
I think both models are extremely valid approaches, and obviously each company is extremely successful. After all, these are two leading titans in the technology industry and major players in the US and world economy. Sometimes you want a tool that is as versatile as a Swiss army knife - and at other times, you want a tool that does one thing and does it well.