In other words - "OOOPSIE! We were 'mislead'. Sorry about that! Nothing more to see here, let's just move on!
"I've apologized. Can't we all just move on? It's Karl Rove's fault."
Dan Rather slandered two men (George W. Bush and General Staudt) and he put words in the mouth of a dead man (Colonel Killian). This apology is meaningless without direct apologies to GWB, General Staudt and the family of Colonel Killian.