Well, there is an auto-refresh which you can configure on a feed-by-feed basis. Edit the feed settings of a particular feed and touch "rss content". You will see the auto-reload option.
Now, one thing to note, if you are multitasking then it won't trigger unless you kill the app and start it from scratch. its really a "check for items on startup". I haven't thought about this feature for a while but it could be triggered when the app becomes active (rather than on startup), and as you say after some TBD amount of time.
Am I on target with what you are asking? We can modify this feature as such.
