Not at all.

Suppose you and I work for the same company. I bust open Skype through decompilation, reading memory, the network, whatever trick I want. With that, I write documentation for how Skype's protocols work.

You read my documentation, and implement it in a new program. Since we haven't talked, and you've never seen a line of Skype's code, you haven't infringed on any copyrights.

It is important to note, though, that this does not necessarily protect us against a patent suit.

If it is done correctly, co-operation from skype is not required. The team that does the reverse engineering will write the specs and documentation from what they learn by examining and analyzing the executable binaries.

They are writing spec documents...

http://developer.skype.com/resources/Skype_UVC_Specification...

it would be nice to see linphone be able to talk to skype people...