Ignore the arguments that WordPress isn’t scalable or appropriate for highly-trafficked sites. If these guys use it, why can’t you?
Runs on WordPress.com, the hosted version of WordPress!
The Wall Street Journal’s All Things Digital
AllThingsD uses a modified version of WordPress MU, the multi-user option.
I count at least 11 blogs running WordPress on Time.com.
So, the question remains: why can’t WordPress run your site? If it can handle these massive sites, it can handle just about anything.