Reverse engineering has given us so many good things - Samba, OpenOffice, Wine, MAME (and other emulators) the bitkeeper debacle, which gave us git. Then there are all the Linux and UNIX drivers that were written by reverse engineering windows drivers because vendors weren't supporting those operating systems.

The guys who reverse engineered Exchange Server were acquired by Cisco.

I don't understand why the Skype case is 'evil'. distributing the binaries may violate terms of service, but it isn't illegal in large parts of the world.