The 7.2 based BottomFeeder development stream now supports Atom 0.3. The only real change I had to make was in the handling of the now (needlessly complex) link elements. I think I agree with Dare Obsanjo on this - there's really no value add to Atom format that I can see - it's just another format for us aggregator authors to support, and yet one more choice for end users to have to weed their way through. Meanwhile, some people are ramming that choice down your throat. Here's what Dare has to say:
The fundamental conceit of the ATOM effort is that they think writing specifications is easy. Many of its proponents deride RSS for being ambiguous and not well defined yet they are producing a more complex specification with more significant ambiguities in it than I've seen in RSS. I actually have a mental list of significant issues with ATOM that I haven't even posted yet, the ones I mentioned above were just from glancing at the aforementioned feeds. My day job involves reading or writing specs all day. Most of the specs I read either were produced by the W3C or by folks within Microsoft. Every one of them contains contradictions, ambiguities and lack crucial information for determining in edge cases. Some are better than others but they all are never well-defined enough. Every spec has errata.
The ATOM people seem to think that if a simple spec like RSS can have ambiguities they can fix it with a more complex spec, which anyone who actually does this stuff for a living will tell you just leads to more complex ambiguities to deal with not less.
Higher levels of complexity does not lead to less ambiguity; it leads to more. Why? Well, think of any board games or card games you know - which ones generate rule arguments - the ones with long lists of rules that attempt to cover all possible situations, or the 1-2 page rulebooks that tell you what you need to know? This is why RSS, with it's supposed problems - has few actual problems in the wild. Meanwhile, watch atom feeds that crop up to vary wildly, as different template authors interpret the complex rul structure in subtly different ways. Bah, humbug.