Regardless of whether or not Kelly has had multiple relationships with other wrestlers, there is something called being a gentleman. Call me old fashioned, but publicly discussing a lady's affairs is something a totally classless guy would do. He was the one who drew first blood in the interview, and the hosts ran with it, pushed it further, and so did he. Going on there and saying "Punk has banged every woman in the industry" is enough of an unprofessional jab, but there is a civility thing when girls are the people in question.
If he wanted to get a shot in, which is dickish enough, it should have been followed with, "No, seriously, she's a really sweet girl. Anyway..." He didn't cover his own ass, or hers, and for all we know, his "apology" could have been forced. Public figures are often forced by their employers or agents to issue apologetic statements after they say or do something stupid. It wouldn't surprise me if Vince/HHH/whomever had to step in. Speculation, but possible.
Let's not forget that Kelly just won the Divas title and has been on a recent push as the female face of the kid-friendly marketing. She did the exhibitionist thing in the past, but look at every WWE Superstar collage and she's often the only Diva featured. A face Divas Champion is supposed to be the standard to which girls strive, according to WWE, and having the #2 guy publicly declare her to be a **** puts her career and credibility at risk, as well as WWE marketing. Granted, not everyone listened to the interview, but word spreads through dirt sheets, forums and word of mouth. A relative of mine worked for WWF back in the day, and finding out about what guys were like in "real life" greatly affected whom I rooted for. I don't think there will be major backlash for Kelly, but I wouldn't be surprised if some people didn't support her as much as they might have before.
Being critical of his opponent at an upcoming PPV is one thing (I still don't agree with what he said, but the possibility of loose kayfabe gives an argument for it); however, he threw Henry, Khali and Kelly under the bus as well, in addition to slagging off someone who is scheduled well in advance to main event the biggest PPV of the year and is being looked to as a significant draw for tickets, PPV buys and merchandise sales. Hopefully Orton gets a sit-down and someone drives the point home that he doesn't have the right to run his mouth to such a degree.