Might take a few more years as we are going to have a lot of really great football players eligible basically every year on for a while. Is he hall worthy? Without question. Think its just a matter of getting in the right class.
Dungy had some real garbage at qb in Tampa though. Though Dungy couldn't win a championship with the qbs he had in Tampa, he does get lots of credit for ending the greatest stretch of futility in NFL history. Tampa lost double figure games for 12 consecutive seasons, an NFL record, stopping the string with a 9 loss season the year before Dungy arrived. Kind of like Cowher, he just couldn't get it done with a group of qbs similar to what Cowher had before Ben arrived. Cowher's high profile in the studio will help him. Unlike say, John Gruden, Cowher didn't take over an already powerful team, nor did the team fall apart under his watch, although the Rooneys were patient as the team struggled through the late 90s rebuild, just as they were during Tomlin's 8-8 seasons.
Cowher was the much better coach and beat Dungy on the road in the playoffs on the way to the 2005 Super Bowl championship but Dungy has always been the media darling and of course the first black head coach inducted into the HOF Cowher's time will come..
Cowher definitely should get in, but I think it will take some time. He basically was the coach of two great eras of Steelers football (1992-1998, 2001-2005), including two dominating eras of defense. Combine this with his overall record, playoff record, division titles, HOF players coached, two Super Bowl appearances and one championship, it is only a matter of time.