Chromium 64bit for Windows appears to be building on Google’s official builtbot. Many users of 64bit Windows will be very happy about this, I’m sure. 64bit leads to potential performance improvements, as well as many security improvements (especially on Windows 8) so this could go very well for everyone.
It will be fun to see what developments come out of Chrome 64bit, and what kind of performance improvements we really see. The potential for performance improvements on a 64bit browser are… mixed, and complicated. Complicated data structures like the DOM won’t enjoy larger pointers and long int values, but there are other performance improvements that will potentially outweigh that.
In terms of security, among other things, Chrome will now be able to use High Entropy ASLR, a feature of Windows 8 that makes ASLR more resilient to specific types of attacks.
Naturally, Linux users have had 64bit Chrome for ages.