What I'm trying to do is create "My Yahoo" for our Intranet site. To achieve this it looks like I could create a "my-intranet" package with a dependency on new-portal. The my-intranet package would handle automatically creating a portal for a user when they hit the page and maintain the relationships between portals and users. I would also then copy the tools used to manage the portlets from the dotlrn package.
Does this sound right?
If you aren't using dotLRN there may be better solutions then new-portal. For instance Don's portal or an XOWiki portal like solution which you can see on solutiongrove.com.
If you are using dotLRN then you do want to use new-portal.