Posted by Andrew.
The Chrome dev channels for Windows and Linux have been updated to 18.104.22.168 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.
I just checked my Chrome on Windows 7 x64 version, it's up to date (22.214.171.124):
When I checked the Chrome process in Windows Task Manager, it's still a Win32 application: