how about that?
how about that
That is very interesting, impressive, exciting, surprising, or respectable. Said as an exclamation, rather than a question. A: "I heard Janet is running for a seat in the senate." B: "Wow, how about that!" How about that. Have you ever seen such a thing?
See also: how, that
Farlex Dictionary of Idioms.
how about that?
Isn't that surprising, remarkable, or pleasing. For example, They're engaged-how about that? [Colloquial; first half of 1900s] 
See also: how
The American Heritage® Dictionary of Idioms by Christine Ammer.
- hoo-rah
 - atcha
 - back at you
 - back atcha
 - ah
 - be still my beating heart
 - be still my heart
 - manual