It seems to me that it would depend on the total content of the page. If you had 500 words of content, with 50 of that being the RSS feed, then I don't think you will run into a duplicate content problem. If the RSS feed was 90% of your page content, then perhaps.
Keep in mind also that other publishers of this feed are likely to have their own unique content surrounding the feed, making the chances of your total page content and their total page content being identical somewhat smaller.
You can even make a seperate page per feed. That's good for your users (readability, if you use a larger font) and does not trigger a SE penalty. As long as you use related feeds which are of interest for your users, you can pretty much do what you want. OTOH if you have an empire of those pages plastered with ads and no other unique content, probably SEs will do exciting things with your stuff in their index. There is no 'duplicate content penalty', it's just that SEs guess the source and deliver that page on the SERPs. Well, sometimes the guess is weird, but that's life. Carefully selected RSS feeds properly used as offsite content and relevant to your site or a section of your site are safe with SEs and most probably a great service for your vistors. What's good for users usually doesn't trigger penalties. However, it's not the method of 1st choice to improve indexing or ranking on the SERPs, IMHO.