In a battle between market leaders; Microsoft's Internet Explorer [65.5%], Firefox [22.5%], Safari [8.4%], Google Chrome faces an uphill struggle [1.8%].
Unlike search/services/advertising businesses, Chrome faces the heaviest battle yet: it offers the same level of experience as Internet Explorer and Safari, and it looks like the customers willing to change their default browsing habits aren't interested in non-customizable browsers.
In order to capture more market share, Google is slowly opening up to browser customization. Website ChromePlugins.org6 released its first two plug-ins, light-weight extensions: Delicious bookmarks and Twitter Notifier [Chritter]. If you're interested in trying Chrome and the plug-ins being developed right now, head over to ChromePlugins.org.