One thing I've wondered about Atom--why doesn't it use the same names as RSS for elements with the same purpose? For example, why call entries "entry" rather than "item"?

I know Atom is not RSS, and isn't pretending to be. I know Atom wouldn't be "backwards-compatible" with RSS even if some elements had the same names. The relevant question is what would be the pros and cons of using the same names. If the pros outweigh the cons, then it would be wise to use the same names. Let's discuss "entry" versus "item":

Con: "Entry" is more descriptive than "item", especially for blog entries.
Counter-Pro: Yeah, for blog entries it is, but Atom is for more than blogs, isn't it?
Counter-Pro: It's not that much better, so if there's a reason to use "item", item should win out.

Pro: If you use the same name, it makes it that much easier and straightforward for a program to handle both types of feeds. This is my main argument: we are, of course, expecting the same programs to handle both, so why not avoid confusion and extra coding when there's no compelling reason to use a different name?

I don't expect Atom to tether itself to or shoe-horn itself into RSS's lexicon, but in cases like this where either name works just fine, using a different name almost makes Atom look like a teenager rebelling against whatever it was the mom and dad used to do, just for the sake of establishing its own identity.

Well, I've ranted long enough. It'll be a teeny bit of extra trouble, but we'll deal with it. Rah rah Atom.