I guess it can be natural to have your fill of working for one company, but... Facebook? What is he going to do, design animations of byzantine security controls that change on a weekly basis? I hope the money's good.
Why would Apple trust Samsung to hold up their end of the bargain? Is there anything in the past several years that would indicate Samsung would follow through on any agreement that might be negotiated, or would they continue to copy features on a wholesale basis?