So I bounced this idea off of Soryu and it seems this hasn't been discussed much. What if you could add multiple carets to the current document by command-clicking? I imaging this to work in a way almost identical to that of the current snippet mechanism. For example: choose three caret locations, start typing, and in each location your text will show up. Press tab and the caret will focus in on the second of the two locations, highlighting the newly typed text (if any). Tab again and it moves to the third.
It would also be ideal to be able to highlight multiple selections in the same way--kind of like a powerful replace mechanism. Command- click and select three words in the document, then type one new word, and incrementally, all three words change to the new one.
Has this been discussed before? It seems plausible given the powerful way we can already "insert as snippet" to the document.