Fairy Tale Face Lifts

The puzzling debate over what really defines intellectual property has been raging for what seems like an eternity. Certainly having access to the Internet and being part of a global society makes everyone much more aware of how difficult (if not impossible it is to be original). The thought that any idea I may come up with has more than likely been conceived of millions of times before is enough to make someone never want to leave their bed in the morning. Obviously we do need certain laws to protect intellectual property when large sums of money are at stake, but where do we draw the line and who gets to draw it?

If Disney is allowed to sue for the unauthorized use of their stories or images, then how come nobody has sued Disney for their appropriations of classic fairy tales such as Snow White, Robin Hood, The Princess and the Frog (just to name a few). Does turning the character of Robin Hood into a fox really constitute a significant enough change to escape laws the guarded intellectual property (if that were the case then I wouldn't be facing a cease and desist charge over the syndication of my character "Marvin Mouse"). 

Presently, copyright laws only protect content for a certain number of years, after a while these timeless classics become public property, but do these laws really provide a conducive environment for fostering creativity, and free expression? Or do these laws only protect the established and wealthy, undermining and stifling any budding artistic endeavors of those with shallow pockets?