the recent release of Google's Chrome browser had many people wondering why Google would want to get into the browser game at all, since they are all about being web-based and standards-compliant. it's interesting to think about this in terms of IE & Silverlight, where Microsoft's main concern is to use a browser to push proprietary technology.
from a certain perspective, Google is in a very similar situation. for the web to become a practical platform for many applications, it still is desperately missing better offline support. Google Gears is an interesting toolkit for blending web-based applications with the local environment, but it requires an extra download and install and probably is not very widely deployed.
so the most important thing about Chrome actually is that it has gears built-in, which turns it into an offline-ready browser. this way, Google can start pushing more advanced web-based applications more rapidly and can do so by distributing a browser with the required functionality. stripping the browser from all the
page-viewing cruft of recent years and turning it into a more minimal environment within which applications then can build their own interfaces also makes sense for the same reason.
however, the basic question is whether a browser should primarily be an execution environment for a Rich Internet Application (RIA), or whether it primarily should be an application for information access and gathering based on declarative technologies such as HTML and CSS. i am definitely voting for the latter, but the question is a difficult one because these concepts and goals are overlapping.
Microsoft and Google are in the web game for very different reasons, but the interesting observation is that they both want the web to be something different than the HTML-only web. Microsoft wants more proprietary applications so that they can get better lock-in. Google wants more web-based applications so that they get a bigger market share of the application pie, and more people donating their data for free to them. very different goals, but very similar methods when it comes to IE & Chrome.