Role-based personalization as compared with complete customization is a good example of this: aggregating and presenting information relevant to a person's role is more likely to be valuable than simply allowing the user to customize a page of their own interests. A user may say they prefer the latter, but the former will resonate most with them.
Nielsen also discusses the importance of cross-functional governance in intranets -- building consensus on standards and parameters while allowing multiple groups to have a voice in the functionality and direction of the site.
One of the most interesting takeaways for me was the portion of the article dedicated to measuring ROI. Nielsen offers six steps for capturing data on ROI, and it's a sound approach. Nielsen and his consultancy have been doing this for years, so you can have confidence that he knows of what he speaks.
The Alertbox article is a solid "state of the union" summary as it comes to enterprise intranet portal usability, but if you're looking for more details and in-depth information, you can purchase and download the full Usability of Intranet Portals report from the Nielsen Norman Group. It's not cheap, but for groups responsible for building their own best practices, there's a lot of valuable information here.