Well, if I recall, Viktor was never said to be a pretty boy. Possibly, they are suggesting that nobody will like the boy cast as Viktor because he won't be as 'good-looking' as the others. That, and he's not a very popular character. He DOES make friends with Slytherins and comes from that 'dark arts' school.
Personally, I imagine that I'll love Viktor... I think he'll be awesome! I just hope he gets enough lines and isn't played like a major bad-guy the whole time. I mean, he wasn't THAT bad.
Very interesting character... can't wait to see who gets it!