Doubt it will happen on any large scale unless the US dropped the import restrictions and tarriffs on foreign sugar, which won't happen because the price collapse that would ensue, would probably put anyone producing sugar in the US out of business in short order.
The number of consumers that would seriously "care" about such a change aren't numerous enough for it be worth Coke's - or Pepsi's effort to make such a change. To most of us here, yeah it would be a big deal, but if general consumerdom were clamoring loudly for this, it would be done. But a lot of people don't give a *bleetp*. They've probably got years of contracts on their supply HFCS lined up as it is.
The growing amount of stories about how bad HFCS can be for some people may, in time, change some consumers' attitudes regarding this though. Time will tell.
And, remember, for those who want real sugar in their Coke or Pepsi, it is produced, in limited markets once a year for to be Kosher certified during Passover. Do a search on this site for "Kosher" and you'll find more info about it.
-Andy
Give me some cane sugar Pepsi in a glass bottle!!