An Enterprise Version of WordPress…

We’re developing a site for an academic institution and will recommend using WordPress as the platform. We’d like to enable students to create their own sites using WordPress and am wondering is there is any enterprise-type of WordPress that would allow us to administer properties for 400 students. Would it be easier / safer to just create sub-domains and install an individual copy on each?

WWWPD?

Thanks in advance for your input.

kp