An article in the Journal of the American Society of Nephrology links pop consumption - specifically throught fructose - with elevated blood pressure. The researchers from the University of Colorado used data from the National Health and Nutrition Examination Survey (NHANES) to look at 4500 adults with no history of hypertension. They adjusted for a range of factors and found that consumption of at least 74 grams per day of fructose - equal to about 2 1/2 bottles/cans of pop - significantly increases the likelihood of high blood pressure.
Another article in WebMD notes that the research is under fire from the Corn Refiners Association, whose members I assume make a lot of fructose, as well as the American Beverage Association. The Corn Refiners argue that the researchers miscalculated the amount of fructose in a pop because it doesn't take account of other sugars used in soft drinks. However, as reported here last Spring, a clinical study by another group of researchers compared glucose consumption with fructose consumption. This group found that fructose promoted an increase of bad fat - visceral adipose tissue - higher lipids, and decreased insulin senstivity when compared to glucose.
The president of the American Society of Hypertension also commented in the WebMD piece - saying that all sugar is bad and that fructose shouldn't be singled out but not really criticizing the science of the research.