CMS & WordPress
What is the maximum number of users that a wordpress blog supports?
I'm not sure that there is a finite limit. Though, if you're looking to place a massive number of users on a single WordPress platform then I might question the choice to use WordPress in the first place. Any system with a massive number of users is most likely an enterprise class system. I absolutely love WordPress, but it's not at the enterprise level.
I would think that it would depend on the capability of the server that you are using. Wordpress should be able to support as many users that your server (specs) can manage.
wordpress has become over the years a almost enterprise class system so it can support quite a few users but this greatly depends on the server.