Test of the Indexes on Knol.
After creating this Knol, I tried to search on the word "Index" but got nothing. I then went to my profile, and selected "My Knols" and it was still blank. So creating a new Knol does not "wake up" the indexing function.
Next I added a category to this test Knol of "Knol". The category appeared in the right-hand panel as normal. I then clicked on that "Knol" category link, which would normally display all the other Knols in that category, but when the page opened it showed No Results.
I then visited the Knol front page, and the entire page was empty. No links to any knols off that page. So something pretty serious occurred.
At 7:00 PST (California time) I notice that apparently all the indexes are now rebuilt, so the Knols once again are displaying.