The lowly speech tag
I think it's time for a general reconsideration of the convention around commas and speech tags. I'm sensing some grumbling among the ground troops (fellow editors), and I think it may be time for some brave style guide author or three to tackle the problem.
Here's how I see it. In the sentence "Juanita said 'I'm coming too,'" the quotation is a clause that is the direct object of the transitive verb said. Simple subject-verb-object (SVO) order, the canonical order in English. If, for variety's sake, we sometimes switch to OSV order ("I'm coming too," Juanita said.), we need a comma between the quotation and the speaker. Similarly, if we switch to OVS order ("I'm coming too," said Juanita.), we need a comma. And if we go all weirdlike and use VSO (Said Juanita, "I'm coming too.") we need a comma. In all three cases, we need the comma because of the inversion and not because of the presence of a quotation.
Now at some point (I haven't been able to pin down when this happened, but I want to say post 1900), writers started to reanalyze the situation and came up with the "rule" that there is always a comma between the quotation and the rest of the sentence. So they back-applied this idea to standard SVO sentences and we ended up with "Juanita said, 'I'm coming too.'" And that's the rule we all learned in school. Quite recently (2005 is the first example I can find, but that's probably not really the first time), we started calling the SV or VS part a speech tag, and now people debate whether something is or isn't a speech tag and therefore does or doesn't require a comma. But I think this is just a result of not analyzing the sentence grammatically in the first place.
I think that if we start consistently dropping the comma in SVO constructions, we'll all be happier, and the style guides will catch up eventually.