Google’s protean appearance is not a reflection of its core business. Rather, it stems from the vast number of complements to its core business
So why is [Chrome] significant? It isn't because "Google Chrome is going to replace Windows" or some other such silliness. As it stands now, Google Chrome is a Windows based application whose most interesting features exist in other browsers. A Web browser cannot replace an operating system any more than an automobile can replace an Interstate highway. The significant end user innovation in Google Chrome is that it is bundled with Google Gears. This means that Google Chrome has a mechanism for delivering richer experiences to end users out of the box. Google can now use this as a carrot and a stick approach to convincing browser vendors to do what it wants. Google can make its sites work better together with Chrome + Gears (e.g. YouTube Uploader using Gears) which could lead to lost browser market share for competing browser vendors if this becomes a widespread practice among Google's offerings. Even if Google never does this, the implied threat is now out there.
Chrome will likely force Google's competitors to up their game with regards to adopting newer Web standards and features just to stay competitive. This is similar to what Google did with online mapping and Web mail, and what the Opera browser has been doing by pioneering features like "pr0n mode" and tabbed browsing. So even if Google loses because Chrome doesn't get massively popular, Google still wins because the user experience for browsing the Web has been improved. And at the end of the day, if more people are using the Web because the user experience is better across the board that's just fine for Google. The same way the fact that all online mapping experiences and Web mail experiences have improved across the board is also good for Google.
I wouldn't be as sanguine about the "replace Windows" bit as Dare is. Particularly not if I was Microsoft. Looking at Asus netbooks over the weekend I'm seeing lots of positive reviews and happiness with the Linux + browser + very cheap hardware package.
It looks to me as though we could easily be approaching, not exactly a "tipping point" (with all the notions of positive feedback that this implies), but at least a period of rapid transition, beyond which the standard or most common computing tool in our lives isn't a Windows PC running MS Office but a $200 - $300 netbook running free software. See all the PC makers playing catch up.
The standard price for this tool is way too low to charge an extra $50 - $100 for OS and Office Suite. And the browser-based email and office apps. will be fine for most users. The entire market for the traditional Microsoft software product, the generic "PC", is evaporating as we watch.