Famous science blogger PZ Myers compares them.
And not surprisingly, Knol looks like crap, compared to WP, at least for the
few subjects he looked up.
Some Jimbo-suckers will probably go around "celebrating" this.
(For the record, I never said Wikipedia was useless, just that it has good
information--plus some incoherent drivel. All watched over by crazy people.
Crowdsourcing a knowledge database still looks like a bad idea.)