Gilead Sciences' (GILD) Sovaldi is now projected to become the best-selling medicine of all time by several analysts. Sovaldi is the first in a new wave of Hep C treatments that promise better cure rates and a shorter treatment course. Some even forecast it would reach $9 billion or more in sales by 2017, at which level it would surpass Pfizer's (PFE) Lipitor and take the crown as the biggest-selling drug of all time. Analysts are trying to outdo each other with optimistic forecasts. According to ISI Group analyst Mark Schoenebaum, if prescriptions were to never grow again, that is...