How many sites/pages have you seen that have received a rank of 5 in a day and appear on the first page of SERPs, often at the top spot? As for number of incoming links, I doubt Knol pages have many from non-Google properties... they've been out there for less than a week.
But think about it. It would be such an incredibly stupid move for google to slay their golden goose just to prop up one of many new projects.
And I am actually unable to consistently reproduce evidence for preferencial ranking. If you search google for "Knee Surgery" knol is #109 and wikipedia is #11. The same search on yahoo gives you knol on #78 and wikipedia on #3
