What is the nuance of 很好?
I made mention of this on my answer to a different question here (which I'll repeat here for your benefit): https://chinese.stackexchange.com/a/890/166

In general, adjectives in Chinese do not need to have 很 to be used predicatively (and thus 很 is not be considered a copula); however the lack of 很 gives the implication of contrast by default. Chinese: A Comprehensive Grammar by Yip Po-Ching and Don Rimmington explains it in this way:


  The presence of these degree adverbs and complements removes any implication of contrast that is latent in an unmarked predicative adjective.
  
  If somebody says:
  
  
    这本字典好。 zhèi běn zìdiǎn hǎo. This dictionary is good.
  
  
  the speaker must be understood to be implying that some other dictionary is not as good as this one. In fact the degree verb 很 hěn 'very', unless it is emphasised, does not really mean 'very', and its integration into adjectival predicative is more often than not to counteract an implication of contrast.