Patcha patcha patcha. Patcha over here. Patcha over there. Patcha patcha patcha. Patcha everywhere! Oh hello, I'm just singing the patch song I sing when there's a new Diablo 3 patch, because Blizzard have just released the patch 1.0.5 patch notes. The patch patches in the new Monster Power and Infernal Machine systems, alongside a whole patchload of other changes.
This will be the first patch ever uploaded to Diablo 3's public test realm, which means it will be available to preview if you opt in to participate in the PTR. Patches tend to bounce around this testing stage for a few weeks before they're implemented into the game proper, and Blizzard say 1.0.5 will be available there "soon".
Monster Power and Infernal Machine are the two biggest changes coming up in patch 1.0.5. Here's what the notes have to say about the former:
"Similar to the "Players 8" command in Diablo II, Monster Power is a system designed to give players more control over how challenging enemies are in each difficulty. With this system, players can choose to increase the health and damage of monsters according to different "power levels" and in return they’ll receive scaling bonuses to experience (for heroes levels 1-59) as well as boosts to Magic Find and Gold Find (for heroes in Inferno) which will stack above the 300% cap. The option to increase Monster Power will be available to all players starting at level 1 in the Quest Selection window, and can be adjusted separately for Normal, Nightmare, Hell, and Inferno difficulties."
And of Infernal Machine:
"The Infernal Machine is a device that will allow level 60 players to battle "uber” versions of some of Sanctuary's most nefarious bosses. While the rewards for defeating these bosses will be great, some assembly is required. Only the most powerful Nephalem can unlock the secrets to building the Infernal Machine, but once forged the device can be used to open portals to special encounters featuring not one, but two bosses which have been augmented from their original versions, both in terms of difficulty and appearance. Defeating each boss pair will provide players with extra items and gold, as well as a chance to find components for a new Legendary ring."
That's some real added value for players looking for not only an extra challenge, but an alternative to grinding the same runs over and over in search of better loot. Other changes in the notes are actually fairly significant too, really fiddly, fan-appeasing stuff: there are two new shrines, a host of auction house improvements, and followers will no longer attack 'idle enemies', meaning they won't wander off and trigger treasure goblins while you're not paying attention.