I have two thoughts on the subject. First is that this is definitely big that Hincapie said it if that is indeed true. So far this is only sources reporting that he said it and I'd like to see actual quotes first. This isn't Jose Canseco we're dealing with. If this is true, this would be like Derek Jeter or Mariano Rivera accusing Andy Pettite (before he admitted it himself). There would only be two people with as much credibility as Hincapie with such an accusation. One is Armstong himself, and the other is Johan Bruyneel.
My second thought on the subject is that I don't care at all in terms of Armstrong's legacy. This isn't like baseball where a sizable percentage did steroids but many didn't. In cycling, pretty much everyone did/does it. This isn't like there's a bunch of clean racers who finished behind Armstong and deserve the titles more than he does. There have been cyclists who have won before and after Armstrong, as well as several who stood on the podium below him, who have admitted to or have been credibly linked to doping. If Lance Armstrong came out tomorrow and admitted to doping at every tour, I don't think he would be deserving of losing his titles since he beat other dirty riders.
His place in cycling history is based on what he did against competition of his time. This isn't like baseball where we compare statistics across eras. Eddie Merkx in his day beat a bunch of competition on equal footing (non doping) and Lance Armstrong did the same, except they were all doping.