how/what 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

how/what about ˈthat (, then)!

(informal) used for expressing surprise, praise, great respect, etc: ‘Have you heard Jane’s been offered a film part in Hollywood?’ ‘Well, how about that, then!’
See also: how, what