Wave was certainly not developed by a hundred-person team. That article says that the "enabling technologies" behind Wave, including GWT and Google's XMPP fork, comprise a hundred-person team, which I could maybe believe between three or four of Google's key infrastructure projects at the time.
I think in Wave's case, as an innovative technology that had no clear predecessor, most of the two years is probably design, not development. Wave missed its mark, so none of that design is really re-usable.
Your job, should you choose to accept it, is to comment on this thread explaining the most awesome thing you've done this since June 1st. You may be as blatantly proud of yourself as you feel. You may unabashedly consider yourself the coolest freaking person ever because of that awesome thing you're dying to tell everyone about. This is the place to do just that.
Remember, however, that this isn't any kind of progress thread. Nor is it any kind of proposal thread. This thread is solely for people to talk about the awesome things they have done. Not "will do". Not "are working on". Have already done. This is to cultivate an environment of object level productivity rather than meta-productivity methods.
So, what's the coolest thing you've done this month?