Rubel points to a BusinessWeek review of Google Blog Search. Too many spam blogs and a not very comprehensive index are among the main criticisms.
Now that Google is in the middle of the spamosphere, perhaps it will focus its prodigious brainpower into vanquishing the spam bots and their pollution. For now, though, Google’s entrÃ©e into blog search doesn’t change much. I’ll be using the engine from time to time, especially its useful tool to find relevant blogs. But even with Google in the mix, blog search is still very much a work in progress.