In the NFL scouting world, 4.3 is the new 4.4. For wide receivers and cornerbacks, running the 40-yard dash in the 4.4-second range is only praiseworthy if you plan on playing running back or linebacker in the NFL.
As far as the "trench men" (offensive and defensive linemen) are concerned, the 40-yard dash has been rendered useless. The 10-yard split is where money is made and lost.
While the 40-yard dash has become the glamour event of the combine, its scouting value varies from one position to the next. Everyone remembers Vernon Davis' incredible performance last year (4.38), but NFL scouts were even more impressed with his results in the 20-yard split (2.52 seconds) and vertical jump (42 inches).