- The surprising thing ... is that they're trying to copy My Yahoo.
As many people have found out, the My Yahoo metaphor of a customizable page displaying static information doesn't scale ... With millions of blogs and other sites of interest, you need a different interface paradigm to deal with all that information.
Each time you visit your My Yahoogle page, it takes time to scan the page to see if there's new information. This is a complete waste. If you only show new things, the amount of information that needs to be displayed decreases greatly. There's less information, and it's all new.
Most people don't have the time to read 200+ feeds every day. At some point, you're going to have to give up on ordering the articles by date or feed and start ordering by relevance.