I have been on two Illuminations cruises, one before they included the snacks in the price, and once since (thanks to a wonderful DIS family). The snacks/drinks are as mentioned upthread. (bottled water, soda and small bagged snacks like chips and pretzels). You can arrange for all kinds of food, cakes, drinks, champagne, beer, etc etc for extra $$. The decorations can be arranged as well. It's really nice to have the decorations, and a cake and champagne.
We never had any smoke. When it was cold, they provided warm blankets.
I am in the minority on this, but I don't think the view is the greatest. It's nice, but the show is much better seen from other vantage points around the lake. There is an island that blocks the whole view around the World Showcase (for example, you really can't see all of the buildings light up, or all of the cauldrons). It's a really nice view, but not "the best" view you could have. The show was designed to be seen from the front of the lagoon, not the side where the boats park. It's still a really fun thing to do and we would (will!) do it again in a heartbeat!
It's unfortunate they can't park the boats somewhere that really gives you a "perfect" view. You know, come to think of it, I think what makes the view nice is not having to "fight" the crowds and stand elbow to elbow during the show!
Also, my one other complaint is that they basically boot you off the boat afterwards--as soon as they drive straight back to the dock after the show is over. I would prefer to continue cruising and relaxing on the boat for awhile, or at least until the crowds have gone away, lol. But, then again, we love boating and water, and we would take this cruise even without the fireworks, lol!!