Since yobidashi means "calling out," you'll hear it in non-sumo contexts as well. For instance, if you hang around the arrivals hall at New Tokyo International Airport, you'll hear the following enough to make your ears bleed:
お客様にお呼び出しを申し上げます。
O-kyakusama ni o-yobidashi o môshiagemasu.
Paging all passengers.
Oh yeah, I know what you're saying. "It takes them seventeen syllables to say what we can say in six?! What kind of smacked-up, cracked-up, wackity-wacko wack is that, Jack?!" Well, it's commercial Japanese, which dictates that you have to make everything sound long and important. Compare the following two sentences:
ご協力をお願いいたします。
Go-kyôryoku o onegai itashimasu.
We ask for your cooperation.

早くやりなさいよ!
Hayaku yari nasai yo!
Hurry the fuck up and do it!

The latter is prolespeak; the former is the language of the yobidashi. You hear it wherever there's a loudspeaker and an audience to be loudspoken to. If your train is coming in, for instance, you'll hear something like:
間もなく電車が到着します。
Mamonaku densha ga tôchaku shimasu.
The train will arrive shortly.
A normal person would probably say "Densha da yo!" which means "It is a train!" and, by sheer coincidence, contains the same number of syllables in both Japanese and English.

See, Japanese is a language that can be gloriously blunt at times, but that has to be strained when you're using it in public, especially to people who are paying your salary, and especially when you're thanking them. Like this little gem I heard upon my arrival at Dallas-Fort Worth:

アメリカン航空をご利用くださいまして誠にありがとうございます。
Amerikan-kôkû o go-riyô kudasaimashite makoto ni arigatô gozaimasu.
Thank you for flying American Airlines.
23 syllables in Japanese versus eleven in English. But because it's a yobidashi, the extra syllables are important, and you can't leave them out because some old lady is going to be offended and send trained ninja armies to shuriken your pet kitten into kitten kaboodle.

In a way, I suppose this kind of language is useful, because it lets you feign respect through your grammar regardless of whether you actually respect the other person or not. That isn't a luxury we really enjoy in English, but Japanese people get to ham up their conversations every day. I do some work every now and then on the Japanese Wikipedia, and the people there actually talk to each other in yobidashi-like language, which is really creepy at first because I start giving them the voices of JR conductors in the back of my head, saying "The next station is Tsukamoto, Tsukamoto."

Loudspeaker Japanese is not for the faint of heart. Indeed, I usually prefer the American way, which is to speak softly and carry a big stick.