Maybe 3D TVs won't go away, but are you sure your optimism is because you were recently at the CES ? 3D TVs have indeed been tough sells and the electronics manufacturers are just not used to sticking with products that do not sell in large quantities. There was a time when this was not true, where new electronic gizmos would have a long life and enjoy strong prices (VCRs, Walkmans, portable cassette players ...) but not any more. SIgnificant technology jumps such as DVDs, flat screen TVs quickly become commodities and their prices drop precipitously. This has not been the case with the 3D TVs and hence I see trouble ahead.
Back to the OP, I normally just pay for the movie ticket and either carry in a cup of water or sneak in a can of pop. I can live without food and snacks for 2 hours. I think the concept of popcorn and coke is more due to force of habit for most people anyway.
Do you come from the elite Michael Bay school of movie watching ? TTSS was brilliant, IMO.