An expression of surprise or astonishment, especially regarding some recent revelation. Bob: "You know, if you run your washing machine at night, you can save a lot of money on your electric bill." John: "I'll be, I never knew that before!" Well, I'll be!

Who says well I'll be?

The term monkey's uncle, most notably seen in the idiom "(well) I'll be a monkey's uncle", is used to express complete surprise, amazement or disbelief.

What does I'll be right with you mean?

I will be right with you: I will come to help you very soon.