Atorvastatin was first marketed in 1997 as LIpitor and is one of the most successfully marketed drugs of all time. The marketing techniques used by Pfizer are now a model for new drug introductions throughout the world. As Sqad says, it is now the best-seller but is also the most expensive. Thankfully, this will change shortly in the UK as generic versions of the drug will soon become available.
As far as muscle aches and pains are concerned, these effects occur in around 4% of all (ie not dose related) patients taking Atorvastatin, which is less than some of the older statins.
Returning to the aspirin issue, multiple small bleeds in the small intestine are known in patients taking aspirin as Sqad says, but I agree that these have to put into context and I firmly believe that the advantages of aspirin therapy do outweigh the small risks. Thankfully, MrsProf agrees with me!