A can of Coke could soon cost New Yorkers more than just calories. Gov. Paterson, as part of a $121 billion budget to be unveiled Tuesday, will propose an "obesity tax" of about 15% on nondiet drinks. This means a Diet Coke might sell for a $1 - even as the same size bottle of its calorie-rich alter ego would go for $1.15. Paterson's budget also calls for a 3% cut in education spending, a $620-a-year tuition hike at SUNY and a $600 increase at CUNY - and about $3.5 billion in health care cuts, a source said. The Democratic...