fdmaxey wrote:
"Usually it is said when a speaker is introducing another speaker and the 1st one has said all the details about the 2nd and has complemented him/her enough."
It really just means: "Without further delay or distractions." It can certainly be used to introduce someone: "Yada, yada, yada... And, without further ado, I give you Mr. X, the famous illusionist." It's certainly not used in that context exclusively, though. Like:
"Without further ado, the couple went to the next inn."
Etymology: Middle English, from 'at do,' from at + don, do; to do.