Not necessarily, they all use different measuring techniques. I have many site very high google and not even listed Yahoo.
For now, I am concentrate to be top listed in google search engine.The more search engine notice your existing the more profit you can make
Not necessarily! Different algorithms mean different results. Concentrate on Google. I'd rather be top there than top on yahoo!
I think this was just a post to up his post count. It sounds more like a statement then more of an open question.
Other search engines will probably favor other techniques but it doesn't mean you won't rank at all. If you can rank high in Google, good chance you'll show up in other search engines just maybe not as high.
I completely agree with MaskedMarvel. If you are at the top of google then you are at the top of almost every SE.