Bitcoin is really hot now, can there be no good person to write another bitcoin to circulate with it?
No. If its not Bitcoin, then it cannot be considered as Bitcoin. It is a cryptocurrency.
Is there any significance or value for the second bitcoin?
Look at the altcoins. If they have value, then I don't see why another alt-coin can't. The amount of money it is worth is dependent on how much people are willing to pay for it.
Or ask the question, if there is a second bitcoin, will the current bitcoin and the world have what effect?
Nothing. Alt-coins are popping up by thousands and they didn't affect Bitcoin.