I gave the new Basic DMG PDF a quick look through. It weighs in at about 60 pages, and contains a decent selection of monsters, some common NPCs (thankfully in a separate section, so they aren’t mixed in with the monsters) and a few magic items. There’s also a few pages on building encounters, though no guidance on how much treasure to give. Between the two PDFs you ought to be able to run a ‘basic’ game of 5e now.
One neat thing, certain powerful monsters can have Legendary actions and Lair actions. These are additional actions the monster can take under certain circumstances. For example, an Adult Red Dragon can make a wing attack after another character completes an action; likewise, the dragon can use special ‘Lair’ actions while in its lair, such as magma eruptions or clouds of noxious gas (while the game expresses this as an action taken by the dragon, it is perhaps better to think of them as environmental effects of the dragon’s preferred habitat). This is a neat way to represent the awesome power of a powerful dragon, like Smaug.
According to the basic rules, characters can now ‘auto’ detect magic items, and determine how they work with just a short rest. Definitely not happy about that, but it’s something easy to change with a house rule.
Some items require attunement to use (such as Gauntlets of Ogre Power, for example), and a character can only use 3 attuned items at a time. This is a neat, simple way to limit the number of items a character can use, though I’m sure the full DMG will change it (when it’s released in a couple of months).
And for what’s it worth, the new version of the Player’s PDF just seems to add Forgotten Realms deities and factions. There may be some other corrections and changes buried in the text, but I haven’t given it a thorough lookover.