Not sure what others think, but I prefer to push people toward the right path for the future, which is to just use .format(...) (at least as far back as 2.6).

But when you see the % Operator in the wild you should already have heard about it before, so i think it's worth mentioning.

I think it might be clearer to make a note of formatting techniques after the concatenation section, not within it. Otherwise, it seems like you're implying + and % are equally as good for the third example:

foo = 'foo'
bar = 'bar'

foobar = foo + bar  # This is good
foobar = "%s%s" % (foo, bar)  # This is good? I don't agree =)

Formatting is meant for, well, formatting - not concatenation. Maybe a final paragraph like:
"If you're trying to fill in a template or format your strings for output, use .format: [quick example]".

Actually, I didn't say in the note that formatting and + approach are equally good, besides formatting with % is slower than the + operator if you concatenate two strings. Here, I just pointed out the role of formatting within the concept of string concatenation. If someone gives a fully-detailed explanation about string formatting separately, it can be done in a different section and maybe linked with this note as well.

PS: Anyone keen on writing the string formatting section, should in my humble opinion discourage the use of % operator whatsoever.

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