A recent post to these blogs argues that searchwiki has features that make it overly complicated and very un-google like, the opposite of the elegant simplicity that is the hallmark of their success. I agree that this project seems a little too tech-nerdish to succeed, and even if they pull a Microsoft on it (you know, put it out half-baked then fix it incrementally until it succeeds) then they will won’t be Google anymore.
I do think that a pet project like this one won’t make any difference as long as they keep being exceptional, like combining video chat with their gmail and adding features to their mapping till it becomes something that is unique. As long as what they put out continues to be compellingly useful, they will continue to succeed. When that is no longer the case, then someone else will take their place.