I do like that they've added a default setting and starting town to the DM's Guide. They haven't done that since the red-boxed Basic and blue-boxed Expert sets for original D&D. Too bad they didn't include any rules for quickly resolving army battles or getting land, though...
I looked back at the old Rules Cyclopedia (compiles the red-boxed Basic, blue-boxed Expert, aqua-boxed Companion, and black-boxed Master sets into one hardcover, including a detailed wilderness hex map of the Known World), and the rules covering becoming a landowner with peasants that work the farms and stuff only take, like, four and a half pages. Including figuring out whether the peasants rise up against you this month!
But back to what I was saying, I like that they added the town of Fallcrest to the DM's Guide, and that they included a description of Nentir Vale, which is the area surrounding Fallcrest.
And as much as the basic engine for the game has completely changed, I see great potential for fun in it...
Oh, here's an interesting bit: You start off at the beginning of the day with 1 action point. When you reach a "milestone", you gain another action point. A "milestone" is reached every time you finish two average encounters (and there's detail on Skill Challenges, a non-combat type of encounter). If you take an "extended rest", then your action point total resets to 1. The idea here is that the action points somewhat replace the abilities you use up during encounters, so hopefully you'll keep adventuring instead of taking a rest.
Here's another interesting bit: You have "at-will" powers that you can use as many times as you want. You have "per-encounter" powers that you can use once per encounter. You have "daily" powers that you can use once per day. Per-encounter powers reset when you take a "short rest" (5 minutes). You can take as many short rests per day as you want. Daily powers reset when you take an "extended rest" (6 hours, I think). You cannot take an extended rest if you've already taken an extended rest within the last 12 hours.
Here's another interesting bit: You have "healing surges", which when you use them cause you to regain 25% of your hit points. Using a healing surge is a standard action. More combat-focused characters have more healing surges per day than others. This means that characters are much more self-reliant than before, with a healbot/bandaid simply not being necessary anymore.