Generic-drug makers powered into the top 20 industry groups this week, up from a No. 161 ranking just eight weeks ago. A top draw in that advance, Hospira (HSP), topped analysts' earnings estimates by a wide margin Tuesday. Hospira was a 2004 spinoff from diversified drug giant Abbott Labs (ABT). It has surged 122% from its low in March and is just below its February 2006 all-time high. More than half of Hospira's revenue comes from injectable