You know, some people drink coffee because they like the flavour, not because they need caffeine :P (As a matter of fact, I consider caffeine to be an undesirable side-effect of delicious coffee...)
Coffee isn't the only natural source of caffeine, and yes, it can also be made synthetically.
I've found decaf made with the Aeropress is actually surprisingly good. I usually only have a single cup of caffeinated and then follow up with a few cups of decaf.
I am of the understanding that we currently produce liquid nicotine from tobacco leaves, and use the liquid nicotine for electronic cigarettes.
We certainly can already produce caffeine independently of producing coffee, and while that may be a major reason for coffee production, i doubt many coffee drinkers would be satiated with a caffeine pill every morning instead of their cup of coffee.
Kind of akin to seeing the wine grapes are going away and saying, well we can produce alcohol independently of wine - its true, but it wont satisfy wine lovers.
If we were to replace coffee beans, we wouldn't just offer them a No-Doze; I imagine you develop coffee flavors that could be used to reproduce the actual beverage. No reason for instant coffee to ever have been coffee beans in the first place if you can do the flavors right.
Or, the culture just adjusts to a different caffeine-infused hot drink.
Honestly though, I'd be less upset about coffee going away as a source of caffeine than it going away as a drink. It's so wonderfully delicious that synthetic caffeine just wouldn't really cut it for me.
Diet Rite is my cola of choice. No Caffeine, sweetened with sucralose instead of aspartame. They could use some help with their product packaging, it looks a lot like generic/store-brand soda :)
What do you mean by 'good cola'? Coca-Cola has caffeine free variants of both Diet Coke and Coke Zero. Up here in Canada you can usually find them at major supermarket chains. If by good you mean not Coca-Cola or Pepsi... well then ya, there probably aren't many choices.
Coffee isn't the only natural source of caffeine, and yes, it can also be made synthetically.