> The question is how many people set (or have by default) right language
> in browsers ?

Most don't even know how. That's not a cn issue, but rather a
webdevelopment issue. A well-designed site will have links for the
languages it serves on all pages, so that if the user has a default
english browser and yet only speaks (or prefers but didn't set)
spanish, can still choose accordingly. (Then the site has to set a
cookie or use a session to keep spanish, otherwise the next click will
take the user back to english. But, again, that's a webdevelopment
issue.)

I agree with Jeff Waugh on the images. If i have a site with old GIFs
(due to transparency for instance) and want to pass to PNG, cn would
be a plus - i can change the files all i want and still have the same
URI. (I could even set a filter so that if the client claims to be IE
just stick to GIF...) Unfortunately so far only Opera supports SVG.

Also a plus on text/html vs application/xhtml+xml but i'm still a
little blurry there.

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