Other trackers disagree with those numbers, putting the amount of Chrome users a little under 1.5%. Others don't even have data available yet.
These are definitely skewed perspectives. The browser is only a few days old, so many people may just be test driving it and don't plan on keeping it. Further, that's only two datasets. Other sites may differ. It definitely shows that Google's advertising methods, which include word-of-mouth, are working to their advantage. What I'd really like to see is download figures straight from Google – which I'm sure they are capable of providing.