Browsing through hxxp://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwxp/html/securityinxpsp2.asp about Execution protection (NX) in coming WinXP SP2, it looks like it will have influence on behaviour of some packer/encryptor, though it affects only Athlon 64 or Itanium. How do ya unpacker guys think about this?