IMO, since you put effort into placing the links on your site. You should not use the nofollow attribute. The nofollow was designed to allow Webmasters to specify which links do not deserve the link pop. They recommend you use it if you have a guestbook, comment access to blogs, trackbacks and so on - all areas where you can not control the level of links outbound.
But with RSS, you are asking the publishers for the content. The least you can do is link back with some link pop.