Politics aside… who really cares?
There’s been much said from various mucky-muck tech studs (you can search it out for yourself if you care) talking about the benefits of atom vs rss and why the other sucks, or why one is just so superior.
From a user perspective, I want a feed format that lets me subscribe to a site and read it via aggregator (web or local). I only have a few ATOM feeds, and have mostly RSS feeds, though I’d be hard pressed to tell you which flavor they are .9 or 2.0. Once they are subscribed in my aggregator, I have no way of knowing whether I am reading one vs. the other and don’t have any desire to think about it either. All I really care about is the full article… excerpts annoy me since they require that I take an additional step to read something and really break up what is an otherwise efficient process. I still subscribe to excerts though since I like getting informed through my aggregator first. As local aggregators advance and include web browsers, it becomes easier to keep things streamlined within a single application…
The important thing to remember is simplicity. As more people adopt syndication and large media companies offer feeds as well as the existing blogger camp, no one will want to try an sort out what button to press if you offer multiple versions. It’s hard enough to figure out what to do with the link, since browsers either download the file, or display a lovely page of XML. Users (and it really should be about the users) want a positive, easy experience so that they can understand why syndication might work out to be of great benefit to their workflow or reading list.
There is a good discussion in the comments of a post by Scoble to which I have contributed.