Update: Nvidia has apparently decided to open pre-orders today instead of May 20th as originally announced. You can buy yours for $350 at Newegg, GameStop, and Canada Computer, as well as Nvidia's Shield site. The estimated ship date also appears to have moved up from 'end of June' to June 4th.

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Nvidia surprised many of us by announcing a dedicated gaming handheld during the company's CES press conference earlier this year. Codenamed Project Shield, the device went from idea to prototype in less than a year. Now, Nvidia is all set to take the final step into commercial product, announcing that pre-orders for Shield will open on May 20 at $349, with shipments expected reach customer's hands by the end of June.

Based on the new Tegra 4 mobile chip, also announced at CES, the device comes in the shape of a console gaming controller and includes a 5-inch capacitive touch screen with 1,280x720 resolution. Tegra's four CPU cores and 72 graphics cores support a maximum resolution of 3200 x 2000 pixels, however, so games can be played at full HD on a TV. Other specs include 16GB of storage, mini-HDMI, micro-USB 2.0, GPS, Bluetooth 3.0, a microSD card slot for storage expansion, 802.11n Wi-Fi, integrated speakers, and a headphone jack.

In terms of software the Shield will ship with an un-skinned, "pure" version of Android 4.2.1 Jelly Bean, and as such it should be able to receive any updates Google releases in the future without much delay.

Nvidia's Tegrazone will be the main storefront for Shield-optimized games -- currently there's 76 of them including Max Payne and Grand Theft Auto: Vice City. Naturally, the Google Play store will also be available for a vast catalog of apps and games that aren't featured on Nvidia's storefront.

In addition to running Android games, the Shield can also stream games from your GeForce-equipped PC to the controller via Wi-Fi, where you can play them directly on the small screen or output to a TV. Paired with Steam's Big Screen mode this means you can navigate your library and launch games without moving back to your PC.