If you're the antsy type, you can grab the "Chromed" version of the popular Firefox extension Better Gmail right here, right now. However, you'll need a little patience to install it: this is a collection of the raw Greasemonkey scripts, and it will require some fiddling before you can get them to work in Chrome.
First off, you'll need at least the most recent beta release of Google's browser, which supports scripts. If you don't know which you've got, go to Tools and About Google Chrome. If you've got a version 1.x, you'll need to upgrade, and we're going to take a detour to explain a quick way to do it.
This part's actually fairly easy. Grab the Google Chrome Channel Changer. When you double-click on it, change from the stable build to either the beta or the developer's build. The beta is the more stable of the two, if this is entirely new territory for you.
Close the Channel Changer and run Google Chrome, opening the About window again. It should prompt you almost instantaneously to upgrade to a newer version. Once you've installed it, grab Better Gmail for Chrome and shut down the browser.
Next, point your Windows Explorer to your Chrome User Data folder. For Windows XP users, the path should look something like this:
%userprofile%\Local Settings\Application Data\Google\Chrome\User Data\Default.
Windows Vista and Windows 7 users should look for this path:
Inside the Default folder, create a new folder called User Scripts, and then extract the contents of the Better Gmail for Chrome Zip file into it.
Last step: in your shortcut for Google Chrome, add -enable-user-scripts to the end of the Target field. There should be a space in between "...chrome.exe" and the scripts command. Open up Google Chrome, log in to Gmail, and you should begin to see the effects of the scripts on your Gmail's behavior.
Utilizing scripts in Chrome is nothing more than a way-station on the road to full extension support, but there are some usability problems that an extension and its interface wouldn't have. For starters, removing a script from the folder is the only way to deactivate it. Likewise, to discover what each script can do, you must either look at their names in the User Scripts folder or check out their descriptions online. As simple an interface as the Firefox version has, it not only lets you quickly turn the extension's features on and off, it also tells you how to use them. Without those details at your fingertips, you'll have to hit the original announcement from script-wrangler Lowell Heddings.
The whole process is a definite drawback that is not meant to appeal to average users, and its utility is questionable at best to all but those who are writing scripts and extensions for Chrome. Not all of the scripts are even expected to work.
Complaints aside, it's also an interesting look at how Chrome functions when burdened with third-party features and potentially gives us a small taste of the browser's future.