These days (06/01/08) the Wikia Foundation launched their Search Engine where the ranking of pages by usefulness is now the community's task. Until now, the whole software is in alpha version and can be found at this link.
The software is a little mess, indeed, and many have rushed to sell it as the total letdown of 2008. An overview of the critics can be found in this BusinessWeek article.Of course, this is total nonsense.The software is still in alpha version and it is obvious that its performance will scale when people will start working on it.
Patience is a virtue.