This makes sense, of course — the longer-standing Wikipedia entries should have more inbound links, and ultimately a better Google rank. And Google has no incentive to juice the results to give its own product a boost — if it ever got caught, it would cause its brand irreparable harm.
How do some new knols compare to their Wikipedia counterparts? Wikipedia (SAI 25 #2) did particularly well for nouns like "lung cancer" and "sunscreen," while Knol’s how-to articles like the much-ballyhooed "toilet clogs" and "how to backpack" don’t really have Wikipedia counterparts. Search ranking as of Thursday evening:
|type 1 diabetes||2||30|
|how to backpack||—||3|
Amusingly, if you search for "knol," Wikipedia’s entry still comes up higher in Google’s search results than the Knol project homepage.