What was your intention for the domain? .WS is covered by UDRP, so if Cartoon Network takes offense at your registration, then yes they very likely can take it if they filed a dispute against you.
To clarify (because this statement is not completely accurate)...
Yes, they can come after you if they feel it warrents action. Just becuase you register it does not guarentee they "will sue" even with developement. It is how you develop the domain and if it constitutes "bad faith". And yes, using it for commercial purposes is instant "bad faith".