Excellira - 3:14 pm on Jun 10, 2009 (gmt 0)

Buckworks is correct that the blog will receive and pass PR if you cross-link effectively. There may not be a 1:1 relationship in link value however. In the near past the SEs (G in particular) treated them as separate entities but those lines are gray now. In a subdirectory every link (with value) is counted towards the domain.

Also, WP is an excellent blog but in your case, why not look for a Java-based blog? It may have less features but it will be a lot simpler to implement and maintain.