One of the basic properties of old world programmed media was the fixed time slot. This was a particularly defining feature of the news. There had to be exactly 30 minutes (or whatever) of news to fill the slot. If that day was slow, the news was padded with light stuff, if that day was hot, then the light stuff was dropped as were other moderately important features.
You would think that that approach to media would be one of the first to drop online. We may, perhaps, be forgiving of the online presence of mainstream media - there is a fixed real estate on their front page. However, having become aware of the issue, I'm less forgiving of Web 2.0 aggregators including: memeorandum/techmeme, TailRank and even our own BlogPulse. Take techmeme for example. Stories are ranked according, in part (I'm guessing) to how many citations they get from which bloggers. However, on one day, a story with citations from A and B may appear on the front page whereas on another it may not - depending not on how important that story is absolutely, but how important it is relative to all other stories.
I say that we should be looking for interfaces to information that reflect how important that information is and which don't persist artifacts of the very media that we are (apparently) trying to escape.