So you're getting married, are you? How nice.
So she thinks sh's going to become a doctor, does she? Well, well.
You think you're funny, do you?
'Same-way' tags can be used to ask questions. In this structure, we use the main sentence to make a guess, and then ask (in the tag) if it was correct.
Your mother's at home, is she?
You can eat shellfish, can you?
This is the last bus, is it?
[i]I'll...shall I?[/] can be used to make offers
[i]I'll hold that for you, shall I?
My feeling is that these same-way question tags are used more in British English than in American English.
In addition, certainly in American English, they often express hostility or present a challenge:
*Practical English Usage, by Michael Swan. Oxford 2005