Flickr slide shows sure do make it easier to view all those images being shared on a given Flickr stream, and the ability to do so has even spurred a healthy-sized third market from developers that offer Flickr slide show tools as well.
The most notable new option, however, is the inclusion of the recently added Flickr videos as they appear in the slide shows. While the initial introduction of Flickr videos was met with some disappointment given Flickr's seeming hesitance to move fully into the video-sharing realm, the addition of videos into native Flickr slide shows is another step towards fully integrating videos into the Flickr culture. When you come across a video in a slide show, it will immediately play, and then move on to the next item.