Many people are trying to develop the next Google and many are trying to build image search. These efforts are popular and will remain popular. A series of articles by Erica Morphy gives some of these efforts.
It will be interesting to see disruptive approaches to search. Most approaches that I see in this article and hear commonly about are really incremental and have little, if any, chance to compete with Google. In technology sector, to beat a powerful incumbent, one needs to change the tempo of the game by inventing completely new approaches. Incremental improvements only help incombent adopt those and strngthen itself.
Interesting..http://hakia.com/ seems to use the same kind of principle than WebSifter…But I guess that once again, if Google wants to take this approach, it should not be a problem for them..