Posted by Andrew.
The Chrome dev channels for Windows and Linux have been updated to 4.0.203.2 on August 28, 2009. Chrome for Linux is now truly 64 bit with this update.
You can find out about getting on the Dev channel here: http://dev.chromium.org/getting-involved/dev-channel.
To get more details about this update, please visit official Google Chrome Releases Blog.
Chrome for Windows x64 is still a Win32 application
I just checked my Chrome on Windows 7 x64 version, it's up to date (4.0.203.2):

When I checked the Chrome process in Windows Task Manager, it's still a Win32 application:

More information about Google Chrome and 64 Bit
#1 wajdi posted on September 05, 2009 21:15 PDT
wajdi
#2 Markeh posted on September 10, 2009 20:19 PDT
This could be due to sandbox, the 32 bit tabs. probably trying to keep them on a low level? They don't need that much memory anyway.
Can't wait to have true 64 os and softwares! Good job on chrome working toward this on more os, great food for though to think about how much work was done. Always hungry for more great news like this :)
Update News: Google Chrome for Linux is now truly 64 bit