I saw the interview, it was a bit different. Saward is right that the quote was taken from the book, in the same words, just omitting unsuitable part.
The full transcript of the Wrooom book text pertaining to this issue was published here
last week. It reads:
FA: "In the last few years I've had two main reference points in Lewis Hamilton and Sebastian Vettel, but I have a different opinion about each one of them. I consider Hamilton to be a very quick driver, aggressive and totally focused. All he's interested in is winning. Nothing else. A really talented driver. In my opinion Sebastian hasn't quite got to that level yet. I know that he's world champion and that he'll win another championship in 2011, but that's the way it is. For me he's just slightly below Lewis' standard."
VR: "In the course of my career, I've come across all kinds of different riders. I guess at the moment my two main rivals are [Casey] Stoner and [Jorge] Lorenzo. When one's rivals are as fast as they are, they become your objective by also acting as a stimulus for one's own performance. They're very different from each other. One of them is very talented and very strong mentally; the other also very talented, very instinctive but still always very fast."
So Saward is right in that it was an interview undertaken last year (which the Autosport Plus feature stresses), Sport Bild is wrong, but both are a week late.