Probably for the same reasons that Microsoft bought a little browser then turned around and made it free. Applications are moving to the web, and they want to be there. That's where the money is.-Renegade
Have to agree with
Renegade and
Paul Keith on this. The answer lies [somewhat] in 1995 and the lengths Microsoft went to make it so easy to use IE over any other browser. That crazy time with Navigator really set the open source movement on a path that has slowly evolved into Chrome. Apple doesn't give a frick what you think about Safari; they're in control like it or not. Microsoft is racing to install cloud services throughout its software lineup. But right now (beyond Opera), you have three choices: (1) buy into a closed proprietary system like Apple, (2) go with Microsoft, who refuses to implement key open source standards in its browser, or (3) go with Chrome, which is trying to shed as much proprietary baggage as possible for one simple reason: so you can "take your data with you" -- whether that be mobile/tablet, desktop, netbook, and even gaming within the browser.

One example is WebGL (Web-based Graphics Language). What it does is use JavaScript to implement the use of 3D graphics within the browser. Currently this can only be done in Chrome, which makes version 9 a significant step in browser technology. Firefox and Safari are both expected to support WebGL, although Microsoft has not said that they will implement it in IE. Google's
Chrome Experiments page contains some cool examples of what they're trying to do. (You will need to turn off adblock and other filters.)
Finally, Google has learned user behaviors the hard way: once settled in and comfortable with an application, most users are loathe to switch. If you're accustomed to
Google Apps and Services, you'll likely lobby your company to adopt the same for convenience. Microsoft wrote the book; Google is just following the script.