I think Steve was only discussing the OP's code here. Role="navigation" is indeed handy, so long as (like other landmarks) it's used sparingly per document.
Nav already had "navigation" as a role built-in, for the readers (like NVDA) who already understand the native roles, but it's still good to manually add the role for now (or when we have navigation but no HTML5 nav tags).
Or did something have "navigation" on it in the code I missed?
The way I read it, steve was saying that ARIA roles are mostly redundant, but I may have read wrong. Obviously there are other ways to signal navigation, such as a (perhaps hidden from view) heading element that announces it. Not sure which is better, or if screen reader users really care. Accesskeys seem viable too. It's all a bit much for my widdle bwain.
Yes, on elements who were recognised before roles were ever introduced: checkboxes are known to screen readers, so telling a screen reader that a checkbox has a role of "checkbox" is redundant.steve was saying that ARIA roles are mostly redundant
Roles have use when you're using an element who either doesn't have a role, or doesn't have a role matching what you're using it for.
Landmark roles, though, are different. They are completely new: there were no "banner" or "navigation" roles before. You had to either rely on skip links or a hidden header stating "main navigation" or, usually, the first list you run into that starts with links like "Home" etc.
With landmarks, provided they are on the page and you the user are aware of them (if your screen reader is just set to automatically start announcing stuff about the page on page load), then there's a key you can hit *at any point on the page*, so no matter where you've navigated to on that page already, that brings up all the page landmarks. It's like your own skip link list, which you can call at any time (not just when you run into them at the beginning) that are always the same (the names of the landmark roles are set in the specs for the most part) no matter what page you're on.
To me, this all has way more benefits than accesskeys, which will differ between pages. Though accesskeys can be fine for sighted keyboarders using Opera, but lanmark roles will work in all *other* major browsers and in the newer versions of major screen readers.