Lylirra has confirmed that Blizzard is planning on increasing monster density in various Acts.

Blizzard Quote [source] We're looking at making some adjustments to monster density, and right now we'd like to see if we can get those changes in with 1.0.8. The trick with adjusting density is that, by doing so, we could inadvertently create another "most optimal" route in Act I, II, or IV. It's the kind of thing we'll be doing a lot of internal testing on before hand, and likely something we'll want to have up for additional testing on the PTR. We're looking at making some adjustments to monster density, and right now we'd like to see if we can get those changes in with 1.0.8. The trick with adjusting density is that, by doing so, we could inadvertently create another "most optimal" route in Act I, II, or IV. It's the kind of thing we'll be doing a lot of internal testing on before hand, and likely something we'll want to have up for additional testing on the PTR.

Wyatt Cheng went into a bit more detail on the topic of monster density.

Blizzard Quote [source] Yup! Pretty much this. We're spending time working on monster density in Acts I, II and IV because while optimal routes are inevitable, we want things to be close enough that options exist. Currently we have a situation where a small number of specific runs are twice (or more) as effective as your average run. This margin is too large and overshadows other factors. Our goal is to make the monster density in Inferno close enough that factors such as your skill choices and gear level start to become more relevant. Let's suppose you were trying to optimize XP/hour. What if a cookie-cutter Archon build on MP1 had one optimal run, but an SNS Wizard on MP3 had a different optimal run? Different areas also have different monsters with different abilities. Some classes have an easier time dealing with particular monster types, this can cause the “optimal run” to shift as well. If we get the overall densities closer, these other factors will start to become more relevant rather than the current situation where the raw monster density of a run dominates all other factors. When things are close enough, you may try a run that is a little less XP/hour if it means increased Demonic Essences. Maybe you just really enjoy the art of the Act I jail. Maybe you just want some variety and haven't been to an area in a while. Maybe you want to do a full play through in co-op with a friend. It’s a matter of degree -- these aren't tradeoffs most players would make when the run results in a 50% loss in efficiency, but if the difference is 5-15% then these other factors come into consideration. So, like Lylirra said, our goal is to avoid creating a new “most optional” run, and instead provide players with an environment that allows them to choose from multiple different options.

Travis Day dropped more information about Monster Density and other planned features for patch 1.0.8. These include things such as crafting more than one item at once and Auction House Tooltip comparisons.

Blizzard Quote [source] Ok I've finally caught up on all the responses in every location I could find them! This blog was written a while ago and between when I wrote it and when we released it a lot more relevant ideas came up so I want to mention a couple of them. I'm going to keep this short and to the point so I can get back to working on actually improving the game instead of talking about it. ;) Below is a list of things that players can hopefully expect to see as soon as patch 1.0.8. Mob density Acts 1, 2, and 4 will be receiving some adjustments in Inferno difficulty games. We want to try to make all of the acts as comparable as possible so that players don't feel they always have to farm the same areas of the game repeatedly, diversity is the spice of life. Multi Craft We want to make it easier to craft lots of items, so we plan on giving players the ability to specify how many of an item they want to craft and then to make that many. Want to make 20 Archon Shoulders of Dexterity? Cool, push the button and watch it go. AH tooltip compare Ever wish you could compare the item you are thinking about buying with the item you are wearing? You want it, we want it, and we hope to have it in game soon. In addition to the changes we introduce in 1.0.8 we also have longer term plans to address issues that need more attention. I mentioned a lot of these long term plans in the blog and outlined some of our philosophies that will drive the itemization of Diablo forward. One of those ideas that I saw mentioned repeatedly in response to the blog is the fact that class specific items can roll non class appropriate primary stats, we have plans to change this down the road. While random really is at the core of Diablo in so many ways this is certainly one of the areas where it has no potential to benefit players. Wizards don't use Strength, Demon Hunters don't use Intelligence so let's just remove those as potential random attributes on Orbs and Quivers respectively.

Itemization changes planned for after patch 1.0.8?

Blizzard Quote [source] For right now (since 1.0.8 is still being developed), we aren't going to have a lot of additional details to share about what's included in the patch. As development continues, though, we'll be sure to share more information -- most likely in the form of a patch preview blog like we've done in the past, as well as just talking about stuff in here in the forums. The distinction I was making with my previous post is that most of the changes Travis' discussed in his blog aren't coming with 1.0.8, but are instead being planned for sometime after 1.0.8 ships. (PS - HI WYATT. HI TRAVIS.)