The Notbook Review has a very thourough review of both methods for running Windows on a Mac which has OS X installed, called Boot Camp or Parallels ? The article aims to give you enough information to determing which way is the best way for you to proceed. This is one of the most-asked questions on a lot of Mac forums and websites nowadays so the article is certainly timely and much-needed. People will come to different conclusions on the matter but this article seems fairly balanced.
From my perspective, I removed BootCamp from my MacBook Pro about a month ago. Parallels is a very impressive piece of virtualizaion software.
