If so, any tips on where to buy tickets, it they'll be in short supply, what to see? I'll be in Shanghai in September.

I have not been there, but just spoke to relatives who were and they said that the lines were horrendous, they only got through three exhibits before tiring of waiting and what they saw was not that exciting. I was told that the outside of the buildings were nicer than the inside.

Sounds awful. Thanks - ! I went to Expo 67 (I'm that old) in Montreal and loved it. Thought I might hit Expo Shanghai as I'll be there, but did wonder if it might be incredibly croweded. They've been advertising that they expect 70 million people to see the expo for months now. Sounds like a lot, even for China.

janjohnston, I responded to this question on another thread where you asked me that question. Since responding, I've had a little time to think, and would say that yes, if I had it to do over again, I still would spend a day there. Just use some common sense. When you see the line at the Saudi Arabia's Pavilion past the sign saying "waiting time from this point is 5 hours" as it was when we were there, ask yourself -- what could they have there that is worth a 5 hour wait. All together in my two days there I think I did 27 pavillions plus a couple of the big group ones -- but the longest I waited was clearly under an hour. Did I miss the best ones? Perhaps. Did I care? Not a bit.

Just returned from China and a visit to the Expo. We went only at night-time when the crowds were less and the temperatures were lower but still close to 100 degrees. The heat and humidity left us scrambling from one air-conditioned pavilion to another. We did take a golf cart tour that begins near the expo axis and takes you around areas B and C. We resigned ourselves to just the smaller venues such as Qatar, Oman, Morocco, Indonesia etc . . . and would personally say that it was still worthwhile but not an extraordinary experience. I did wait in line for the French pavilion but can't say that having visited France, that the even 15 minute wait was worthwhile. Others in my group would probably vote to skip the whole thing.

We went late July, two days, and although it was very hot and exhausting, I think it was worth it. We went early - you can pick one main pavillion to see per day without too much queue, I think, but that's about it. The queues are enormous. As for our country's pavillion, I just went and asked if we could sneak in the back way - there was a four hour wait- and was greatful that they let us.We didn't queue for anything longer than half an hour, but still enjoyed ourselves. So many Chinese teenagers wanted their photo taken with DH (white hair is unusual) so he enjoyed himself too!
I agree with G2T, that the French Pavillion wasn't worth the wait. The giant animatronic baby and sopund and light tunnel in Spain's is worth a look, though, and the Little Mermaid from Copenhagen.You can also ride bikes back down the Danish one. We also saw Norway, Turkey (good), & Albania (interesting film, but in Chinese) Australia's is great too, but I wouldn't wait four hour for anything!

We bought our tickets in Australia, but heard there that you can no longer get them from many hotels etc.in Shanghai. There are official Expo shops in Nanjing Lu, and maybe they have them.

Incredibly crowded, outside of building nicer than inside.

Starting from September, you probably need to buy ticket at entrance gate only.