1). Have games available in the Free Play area during the day. Having this area open at 6pm was my biggest single complaint about Expo this year.
2) Arrange to have pin shipping available for anyone that wants to buy a pin at the show. I read somewhere that shipping was available, but none of the sellers seemed to know about it.
3) Get Staples or some office supply house to sell tubes for translites and boxes and tape for parts. I bought far less than I wanted to because there were no packing materials available. I did end up going to the post office, but it was such a hassle that I won't do that again. Go one step further and provide a central packing/shipping service. I wasn't the only person that wanted this. Chances are, if you don't drive to Expo you'll want to ship stuff home.
4) Set up some round table sessions for general discussion on specific topics - advice, tips, etc. have a moderator, but not just presentation/question format. Maybe have a Friday lunch set up like the banquet where people can just talk among table mates.
5) Find some way to encourage vendors to provide better Expo specific deals. Give everyone some "funny money" as part of the Expo package only good in the vendor area, either specific dollar values or % off coupons. Offer some sort of Groupon-type deal where cost is split with the vendors.
6) Beef up the auction. It almost seemed to be an after thought. Provide a catalog/list of the major items in advance. Have some items on silent bid throughout the show. This will allow people to plan (and go to the bank if needed). Make it clear if it is cash only or if checks and/or cards are OK. I would have gladly bid on more items, but I didn't have enough cash to do so (though I was very happy with what I won). Raising over $16k for Make A Wish was wonderful, but you should have been able to hit $50K easily.
7) Get Stern to do an official Q&A show, much like Jack did with JJP. Doesn't have to be just Gary (and probably shouldn't be just Gary, as everyone will just expect him to announce something major). Maybe this year people would have just vented about unfinished code, but the lack of any type of official session really upset a LOT of people.
News on Star Trek was expected at the Launch Party, but there was no "launch", just the same machines moved from the free play area. If I was marketing for Expo or Stern, I would want some sort of talk/presentation and swag (other than a flyer) available or even raffled. T-shirts, posters, etc. Stern branded, co-branded whatever. A wonderful opportunity to market to the target audience most likely to buy/play/promote/evangelize a new pinball was simply squandered.
Both the Expo and major vendors are major draws. Have someone that understands marketing market.
8). Have some sort of daily news update sheet posted in a prominent place. Use it to squash rumors or for vendors to make announcements.