i guess it means"has it been done?"or"was it done?" =)

generally it means "have you done that?"

1.means：so something happened? for example: people1:she and he stayed together in a room last night. people2: 那什么了吗？ 2.use 什么 replace what you want to say but forget . for example: people1: she invited me to her party. people2:那什么了吗？ people1：what? people 1: did you go with presents? so when someone say 那什么了吗 to you, you can guess what it is meaning. or you must ask what.

In my opinion,it means"you did that?",the most important is "什么"means different in different situations.when something happened,and you want to know if you are right for the result,but it is hard or shame to speak out,then you can use this sentence.

It doesn't have a certain meaning. It need a context to know the meaning of it.