i actually want this badly. RSS feeds is one of the ways i keep an eye on the activity on my forum for the period when i was offline. i do not like getting alerts about all new threads and posts in email. with RSS i can go through them over a period of time as i clean up my RSS feeds.
i have a thread with other requests related to RSS feeds. i am yet to get a response from the developers but i do hope they consider them.
i accept that RSS is not heavily used by forum users. but they are still a very powerful feature. and the way XF is programmed... i do not think it would take a lot of effort to provide these functionalities.