I just found out about this game today. It looks very impressive and I look forward to the demo. It was hard to choose from the list of options. I ended up voting for "Fun in the game", because when it comes down to it. That's what we all want. Fun. One could make the most realistic sim ever and it might not turn out to be fun at all.
I also think graphics are important, not just for the eye candy, but it can also add to the realism and gameplay as well. Having real looking clouds, glare from the sun, reflections of the glass inside the cockpit, things like that. The graphics in this game already look pretty good though and i'm sure it will push my crappy computer to it's limits as is. But I just wanted to say that graphics can add more then just pretty eye candy.
Expansion packs are defiantely important. I always like having big list of planes to choose from. The abillity to add user made planes would be a plus too. (I really want to fly that Vulcan!)
Anyway, i'll be keeping my eye on this game. Looks really good so far. :)