I do not believe it is an infinite combo, for once the opponent's life drops to zero, I can gain no more and they can lose no more, and therefore the game will end, leaving them at zero life.

I have discussed this with many people as well and the combo is not technically infinite because the Exquisite Blood says when the opponent loses life, I gain that much. If they have zero life to lose, I can gain no more and if I am gaining no more, they can lose no more and the combo will stop and I'll win.

Even so, both cards are good individually and the rest of the deck supports the life gain theme. And if the combination were infinite, I should still win because I would have positive infinity life and the opponent would have negative infinity life. Though infinity is by definition an incomprehensibly large number, positive infinity is an incomprehensibly large number above zero and negative infinity is an incomprehensibly large number below zero. So at the end of my turn, my life total is positive infinity and the opponent's life total is negative infinity and I would win.

However, that really does not even apply seeing as I can gain no more life once their life count reaches zero and the game would end.

Why aren't there any shock lands in here? With the lifegain mechanic you can drop them for their 2 damage without worrying about it.

Thanks, I see that according to the rules the infinite loop would end in a draw. But, it seems that whether or not Vizkopa Guildmage and Exquisite Blood together is an infinite combo is rather debatable as I have read on many Internet forums. Thanks for the info, and some places FNM places accept that this is not an infinite loop and others do not, so it really depends on where you play. But thanks again, I always like any kind of feedback, even if it is not what I want to hear.

Thank you for pointing out the no shock lands, I meant to add them in but forgot.

You are correct, the combo ends in a win.