My wife and I went to China six or seven years ago, to visit her parents in Hong Kong. But we also took a side trip to visit Shanghai while we were there. At the time, they were in the middle of massive construction projects, some of which had signs mentioning the World Expo taking place this year.
I didn't give a whole lot of thought at the time to the World Expo (it was just too far off), but the construction was interesting. Not so much for its own sake, but just that it was taking place around the clock, even back then.
The other things that I found interesting about it were the contrast between old and new there, and the fact that we didn't see a single bird while we were there (three days, maybe?). I've been to many cities, and the only one where I can remember not seeing a lot of pigeons was Rome (though even there, there were some). The reason that you don't see a lot of them in Rome, though, is that Rome has a law (or did, the last time I was there, at least) that you can't relocate stray or feral cats. So there were a lot of cats around; in fact, we even saw a ruins that was in the middle of a city square where they were taking care of many of those cats. As a cat lover, I thought it was really cool to see so many cats in the surroundings; I'll have to see if I can find any of my pictures from then.
Getting back to the contrast between old and new there, it was really dramatic. Much of the city looks like I envision 19th century London, while there is a small area that looked very 21st century (there's a reason that part of the city was used as the main setting for Ultraviolet). The contrast was really stark, because it basically occurs (occurred?) along a well-defined line. Since our hotel was pretty much on the line, we could see both sides from above there.
Anyway, getting back to the point of this post, here are some pictures of the World Expo.
It looks like they did manage to add a lot more new stuff since we were there (not too surprising, given how much work was going on).
I wonder if the roads got safer since then. At the time, you had to be very careful crossing the street. Pedestrians definitely did not have the right of way.