New Google Nexus 7 inadvertently revealed by US retailer Best Buy

Yours for $230, the Android 4.3 tablet will ship with Qualcomm's Snapdragon S4 Pro microprocessor

US retailer Best Buy has effectively pre-announced Google's update to its popular Nexus 7 tablet computer, with a specs-packed pre-order listing for the device, now available on the company's mail order site.

The device is expected to be unveiled later today at a "mystery Google announcement", but Best Buy has inadvertently offered a comprehensive preview before time.

The improved device is selling on Best Buy for only $230 for the 16GB version, which gives the impression that Google will be keeping up its subsidised, bargain-price retail model for the machine.

According to Best Buy, the new device - still apparently retaining the title of Google Nexus 7 - will be powered by a Qualcomm Snapdragon S4 Pro 8064, replacing the Nvidia Tegra 3 present in current models.

Other features include 2GB of RAM - twice the amount of the current Nexus 7 - and a high-definition IPS screen. It will be smaller and lighter, weighing in at just under 320g, and will be just 7mm thick.

The Nexus 7 will now have a rear-facing camera, which was missing from the last version, at 5.0 megapixels. The front-facing camera, designed mostly for videoconferencing, will retain its 1.2 megapixel quality.

The new device will ship with the as-yet unreleased Android 4.3 software, and 16GB and 32GB models, as before, will both be available.

There is no mention of any extra data ports - a SlimPort Micro USB 2.0 connector still the only named connector, which potentially rules out space for a Micro SD card.

Overall, though, the Nexus 7's specs look like a fair upgrade to a device that - while still an excellent 7in tablet purchase for the money - is starting to show its age.

The Tegra 3, in particular, struggles when web browser tabs or more graphically intense apps begin to stack up, and last year's Android 4.2.2 upgrade, while adding some welcome new features, hasn't always been noted as being particularly kind to the Nexus 7's middling hardware offerings.