I think you misinterpreted the headline/article. When it says "Tweets" it means "On Twitter" (i.e. "Tweet" has not become a generic term for sharing a link regardless of platform). So it's saying that 35% of the news links posted to twitter.com had to do with Google+.

If I understood him right, I think he means while news about G+ is all over Twitter and in fact, everywhere, the other side of the coin is that even on G+, all you see is discussion about G+ itself. In other words, G+ is still in the buzzy meta phase. Only when people on G+ stop talking G+ that things start to mean something.

Indeed, and I thought Douglas H. would get a kick of something that talks about itself (see his book Godel, Escher, Bach for a ton of recursive stuff...).