This scaling might make some players wonder just

Now that Patch 1.0.5 is running, players have a choice when it comes to monster difficulty. The newly introduced system, Monster Power or the Diablo 3 MP lets players to adjust the strength of the monsters similarly to how they did in the previous installment of the title. As explained in a previous post, monster health, damage, drops, experience and so on is adjusted based on the MP selected by the players. With a maximum Monster Power 10, D3 becomes a bit more difficult. 

This scaling might make some players wonder just how difficult the bosses are on MP 10. The ones that had the curiosity to select the final quest in the game, use MP 10 and check Diablo might be in for a surprise. It seems that the lord of Terror has 470 million hit points. There is no mistake about it. On Monster Power Level 10 D3 has 470.000.000 hit points. So how much time will it take to kill him? 

We will pretend that we have a character with 100k DPS (damage per second). This means it will take 78 mins and 20 seconds. If we divide it by 10, killing Diablo on a theoretical MP 1 will take 7.8 mins. Truth be told it takes about 3 mins. This means that the scaling of Monster Power is not lineear and the difficulty does not increase evenly. With this fact in mind, players might feel discouraged to try and kill the lord of Terror in a one hour long fight just to get a  couple of extra yellow items. Even with an unrealistic 500K DPS it will take around 15 mins which is still unacceptable for such a high DPS. Also, such a DPS could only mean that the character has all the gear it needs and there is no point in farming.

Source: http://www.d3kiss.com