I've tinkered in Blogger to generate a couple rudimentary blogs with Atom xml feeds, and have created a modified homepage that 'includes' the html versions of these blogs. The results are visible at
http://www.locusmag.com/newindex.shtml -- this a temporary file -- where the top few entries under Blinks and in the center column are generated by the blogs, and the remaining entries are hard-coded as they've always been. You can click on the 'feed' links, or copy them to your reader, or however you do it (I've only been trying out readers myself in the past couple days) to see the feeds. You can do so safely because even if the underlying mechanisms for generating the blogs and feeds change, the names (Locus.xml and Blinks.xml) probably won't. If you do this and notice any problems, please let me know. The main entries in the center section of the homepage, now fed by Locus.xml, have involved lots of table tags for the layout, and I worry that those tags, now embedded in the blog template, will interfere with the format of the Atom feed... I'll probably simplify that formatting, with more astute use of style sheet tags, before I go live with the new feeds and homepage reformatting.
Eventually, perhaps sooner rather than later, I will invest in Movable Type and abandon Blogger, which has at least three drawbacks. 1) It's slow. 2) It doesn't let me archive by category (as I do now, manually). 3) It doesn't let me format the dates the way I like (which is either "Wed 8 Dec 2004" or "Wednesday 8 December 2004") -- and neither do any of the freebie blogging/feed generators I've looked at. And Movable Type seems to be the standard.
Further comments and advice welcome...