Inviting a couple of pros is always nice. There are a few out here in Western Canada that you could invite. Some of the Eastern guys might even be willing to come out as well.
As for stuff to do, I'm sure there are some fun little contests that you could dream up, although most of the fun flys that I've been to haven't had any contests of any sort.
Sponsers are always good, as well. I'm a big fan of just having a bunch of friendly pilots there to share their enjoyment of helicopter flying though. Oh, and having food there is always a good thing as well.
I would definately be interested in coming.