A new Harvard study published in Circulation showed that men who drank a 12 oz sugar sweetened beverage a day had a 20% increased risk of heart disease than those who didn't. They studied 42,000 men from 40-75 years old over 22 years. They found an increase in triglycerides and CRP and a decrease in HDL cholesterol; all risk factors for heart attacks. They found no association with men who drank diet sodas.
It is interesting that just a month earlier a study was published in the Journal of General Internal Medicine that showed a 43% increase in MI and stroke if participants consumed one diet soda per day, but no correlation if they consumed a sugary drink. Go figure!