BuddyPress.org

If I understand correctly, Jedbarish is asking if he starts his site off with User blogs turned off, and 50 people register, and he wants to turn blogs on, can he go back and retroactively give those users blogs.

@Jedbarish, if my assumption is correct, then the flat answer is “no, WPMU/BuddyPress can’t do this for you.” However, a WPMU plugin could be made to do this (most likely by counting the number of blogs a user already belongs to,) but the problem is that you won’t know what they would want the name of their blogs to be so you can’t create it accurately. You could guess at their username.domain.com, but it means more manual labor to change it if they don’t like it.