I finished my studies in 1993. Artificial intelligence was my major and I had done a study on programming the game of Go (a review of research state). At that time, the success of brute force for chess had caused much disillusionment in the AI world, which had hoped to see a drosophila. The transfer of this hope to the game of go was present in numerous publications. Even if it doesn't show up very well in a Google search, there are plenty of allusions in articles about programming the game of Go. Since the creation of go language, it is more difficult to find.
John McCarthy described chess as "the drosophila of AI":
http://jmc.stanford.edu/articles/drosophila/drosophila.pdf
Who was it that described Go as the drosophila of AI?