Google will offer three versions of its new tablet: a 16GB Wi-Fi model, 32GB Wi-Fi model, and 32GB 4G LTE model.
The Wi-Fi models, priced at $229 (£149) and $269 (£175), respectively, will debut on Tuesday on Google Play and via a number of retailers in the US. The 4G LTE version will launch "in the coming weeks" for $349 (£227).
The Nexus 7 will also become available in the next few weeks in the UK, Canada, Germany, Spain, France, Japan, Korea, and Australia, with more countries to follow.
The new Nexus 7 has the same 7in screen, but the update takes the display from 1,280 x 800 to 1,920 x 1,200, while the pixels per inch jump from 216 to 323, which Google said is the highest resolution for a 7in tablet and the highest PPI for any tablet on the market.
"Text and images look even sharper," and the tablet lets users watch movies and YouTube videos in native 1080p resolution, Hugo Barra, vice president for Android product management at Google, said during the event in San Francisco.
The new Nexus 7 is also 2mm thinner and 50g lighter than the original, while Google has reduced the bezel size, so it's almost 6mm narrower, Barra said. It will retain the same black-on-black colour scheme.
The tablet runs a 1.5GHz quad-core Snapdragon S4 Pro chipset for a CPU that's 80 per cent faster than the original tablet. The GPU also delivers four times the graphics frame rate, which Barra said is "particularly great news for gamers." Google talked up the gaming experience on the new Nexus 7, which can tap into a new gaming hub - an app known as Google Play Games. Going forward, the store will also make it easier to find tablet-only apps.
Google also doubled the system memory to 2GB, which allows for more apps in RAM and speeds up app switching. There's also dual-band Wi-Fi, support for Bluetooth 4.0, NFC, wireless charging, and more.
The new Nexus 7 now has a 1.2-megapixel front- and 5-megapixel rear-facing camera, as well as dual stereo speakers, and virtual surround sound technology from Fraunhofer, which Barra said is like having a 5.1 sound system via the device speakers or headphones.
Despite these additions, Barra said the new tablet will provide an extra hour of power compared to the original, up to nine hours of HD video playback and 10 hours of web browsing and e-reading.
Android 4.3 Jelly Bean
The new Nexus 7 runs an updated version of Android, known as Android 4.3 Jelly Bean. Among the new features on Android 4.3 is restricted profiles, which allows for profiles with different levels of access. Google pointed to parents, who can disable the ability to make in-app purchases and only allow juniors to open certain apps. But it could also be useful for businesses via retail kiosks or POS systems, the company said.
The OS also supports Bluetooth smart technology, which could - for example - let users pair an Android phone or tablet with low-power devices like fitness gadgets. Google demoed the tech using the Android app for the Runtastic heart-rate monitor, which showed an employee's heart rate climbing in real time.
Android 4.3 will also support Open GL ES 3.0, the latest standard for accelerated 3D graphics, while Google will release a new set of DRM APIs that allow for hardware-based encryption. One of the first companies to take advantage of that is Netflix, allowing for streaming in 1080p HD quality.
Android 4.3 will ship on the Nexus 7. Starting immediately, Google will also push Android 4.3 to the original Nexus 7, Nexus 4, Nexus 10, and Galaxy Nexus. The stock Android versions of the HTC One and Galaxy S4 will get the update "very soon," Barra said.