I want to be able to subscribe to a feed for a limited time. Let me say: “I want to pay attention to this feed for 2 weeks”, or 3 months, or whatever. When the time is up, prompt me to re-subscribe, and show me the dates and contents of a couple of the most recent posts. This would make subscribing to threads on message boards (like Channel9 or MSDN Forums) so much more practical, and it would let me decide to “try out” feeds that I would otherwise ignore.