{from Engadget)

Carefully laid plans for a surprise launch of the long-awaited next generation of the Slingbox were ruined when shelf stockers at Best Buy mistakenly put units out on store shelves two weeks before the official launch date.

The Slingbox 350 and 500 represent major updates in the Slingbox product line. The devices independently stream video, television, and cable programming to remote computers and wireless devices like smartphones without the kinds of copyright and location restrictions imposed on cable, satellite, and telco TV companies’ “TV Everywhere (Inside Your House)“-offerings. In short, if you can watch a channel at home, you can use the Slingbox to stream it anywhere.

Engadget reports the new models seem capable of offering 1080p streaming, assuming your wireless connection is capable of keeping up. The premium 500 model also adds built-in Wi-Fi, a major improvement over earlier Slingbox units that required either a wired Ethernet connection or a wireless bridge. But the 500 apparently deletes the built-in ATSC tuner, which seems to suggest Slingbox is targeting the device more for streaming personal media collections, not streaming broadcast TV. The 500’s inclusion of built-in USB media sharing and HDMI also seem to point in this direction. The 350, obviously a budget model, relies entirely on component and composite jacks.

The larger problem for Slingbox is coping with broadband and wireless usage caps, which could make streaming HD programming an allowance-eater. Slingbox has routinely dealt with Hollywood studios and other content owners objecting to the streaming of their television programming, but usage caps and overlimit fees could present an even bigger threat to their business model.

Slingbox’s Pro-HD and SlingCatcher models — the two most recent major releases — have been around since 2008. The company has since been largely focused on licensing its technology for inclusion in cable and satellite company set top boxes.

Best Buy realized its error when consumers attempted to buy the new units. They have since been pulled from shop shelving but will be back, slated to go on sale officially for an undisclosed price in the middle of October.