Centralized aggregators should not necessarily mean that every user has to read all feeds. There should be both the kind of personalization allowed by personal aggregators (deciding which feeds to subscribe to) but also added vaue services that would allow users to discover additional sources of information and anyway give different relevance to different kind of information snippets that are displayed on the page.
Thanks to Curiouser and Curiouser.
But isn't this simply the description of a portal? The Wikipedia entry on portals says "A web portal is a web site that provides a gateway, or portal, to other resources on the Internet." Look at your My whatever page... Isn't that what you would like to see with your aggregator?
In the My Yahoo model RSS is simply another source of information for the portal to collect. Does RSS need to be the only way to feed information?