NVIDIA has been touting its low-power Tegra System-On-A-Chip (SoC) for mobile devices since early last year, and now – for the first time – we’re beginning to see this system show up in handheld spec listings.  The upcoming Zune HD is powered by the Tegra APX 2600, which gives the player its 720p HD video capabilities.

But this SoC won’t be limited to dedicated multimedia devices; NVIDIA’s Tegra APX series of SoCs will also power future Windows Mobile handhelds, and will provide not only for HD video output, but for a more visually appealing UI as well.

In a press release regarding the Zune HD, NVIDIA states that the company has at least “50 active Tegra processor-based design projects currently in the works.”  At least some of these devices are sure to be Windows Phones, smartphones powered by Windows Mobile 6.5, or (more likely) Windows Mobile 7 which is due out next year.

What will Tegra mean for future Windows Mobile smartphones?  Perhaps most importantly, Tegra will provide the processing power for a new User Interface, which Microsoft has indicated is a main focus of Windows Mobile 7.  Other benefits include superior video playback, faster rendering of web pages in a mobile browser, support for OLED screens, up to 12MP of image processing from a digital camera, HDMI output to TVs and other video devices, device screen resolutions up to 1280×1050, and OpenGL & Direct3D Mobile support.