There's as an existential quantifier

Recently (or maybe this is an example of the recency illusion) I've noticed more and more people using "there's" with plural items. This is not to say I just heard it yesterday, but I remember not having ever heard it before, say, 5-10 years ago. Clearly it was around earlier, because I overheard it in an episode of Friends from their first season, which I believe was 1992 or 1993. A quick google search turns up a movie called "For Every Man, There's Two Women", which dates from 1984. And, in fact, a search of Shakespeare turns up 3 hits (e.g., "There's two or three of us have seen strange sights" Julius Caesar, I, iii). I was, however, unable to find an example in Chaucer, so it could be a mere 500-600 years old. Clearly this is an example of the recency illusion, the tendency of people to believe things they have just heard (or more often just noticed) are new to the world.

I believe what's going on here is not merely laziness. Prescriptivists love to jump all over linguistic innovations, pointing out how they are vague, lazy, or just downright immoral. In many instances, these critics couldn't be any more wrong. Most often linguistic innovations arise because people have a desire to express themselves, and want a better and more succinct (and often LESS vague) way to say what they're thinking. A good example of this is "like," as in "John saw Steve hit Mary and was like 'What the hell?!'" Critics would probably have this utterance rephrased as "...and said, "What the hell," or "...and thought, What the hell. The problem occurs when John neither said nor thought this. The use of the word "like" conveys an emotion via a descriptive phrase, and there is simply no other way to do this in the English language. I'm a very conservative like user, because to me it is marked and sometimes, when used in excess, the subject of contempt. However, I do use "like" in all situations like the above (of course this is in addition to the "normal" uses of like as just demonstrated), because it's the best way of expressing myself.

So why would someone say "There's two pencils on the table"? I would wager not because they're stupid or lazy. I think the most likely possibility is that the contraction "there's" has ceased to be a true contraction, and instead has become a sort of existential quantifier that signifies "There exists some x," where x is a state. In the above example, the state is "two pencils are on the table." Many more people would say "There's two pencils on the table" than would say "Two pencils is on the table," so clearly there is a perceptual difference. People aren't looking at "there's" as a verb, but rather a mathematical or logical operator. Now, this works fine in a predicate logic framework, but I wouldn't want to try to explain it in current syntactic theory. I'm sure someone could, though, so if you're so inclined, please share. Also, if someone can antedate there's with plural argument to before Shakespeare, that would be interesting to see.