They are definitely an great show of respect. Almost brought a tear to my eye when the South Africas formed one for Ponting.
I don't mean to sound horrible but I'm not sure that Hussey really deserved one. Don't get me wrong, he has been a champion for Austalia and well deserving of handshakes from everyone when he gets out for the last time. But if anyone and everyone gets a guard of honour when they retire it kind of loses it's meaning.