Shares of WellPoint tumbled after the health insurer reported a 2nd-Q profit drop & enrollment that slid further than analysts thought. Total medical enrollment fell by 1.1M, or 3%, to 34.2M compared to the 2nd-Q '08. It attributed most losses to rising unemployment. WellPoint, the nation's largest health insurer based on enrollment, said it expects year-end medical enrollment to fall to 33.6M, a 4% drop. Nonetheless, it reaffirmed its full-year guidance. "Given all circumstances, most notably the unemployment rate, we believe now isn