In writing Guerrilla Social Media Marketing Jay Levinson and I developed a quick comparison between traditional websites and social sites. Guerrillas know that to build community and consent your website and homebase must be social.
While he speaks directly to public-facing corporate marketing engines, some consideration of these concepts is worthwhile within the closed confines of a corporate portal. This is particularly the case if your portal supports a hierarchical and globally distributed sales team, as mine does. Including and promoting social elements can be a challenge.