I've been approached by an organization to install Wordpress on their hosting but they are using Convio and Convio is setup to NOT all anything in a subdirectory (ie http://www.domain.com/blog). But, they are offering to install a subdomain (ie. http://blog.domain.com). Now the domain has a HUGE page rank and several tens of thousands of backlinks that I want the blog to benefit from. However, I learned that subdomains before the domain name everything is lost when it comes to backlinks and PR.