The iPad is king in the business world, but HP hopes to overthrow Apple with the ElitePad 900, a 10-inch Windows 8 tablet that's all about expandability. When it goes on sale in January, the 1.5-pound ElitePad will let you add an expansion jacket that includes a plethora of ports along with a slot for an extended battery. You'll also be able to outfit the device with a desktop docking station, a pen and (eventually) a keyboard jacket. HP will announce pricing for the slate closer to launch.

Powered by Intel's latest Atom Z2760 processor, the ElitePad 900 sports a sturdy machined aluminum design, a bright 400-nit Gorilla Glass 2 (1280 x 800) screen and plenty of security features that should make IT departments happy. We spent some time with the ElitePad 900 and came away impressed with its versatility. Check out our hands-on video, gallery and initial impressions.

The ElitePad 900's chief selling point is its expansion options. For example, the Expansion Jacket adds two USB ports, an HDMI port and SD Card slot. You'll also be able to add a battery to this jacket, extending the 9 hours of rated runtime. A separate rugged case provides extra durability, and the Docking Station will let you connect the ElitePad to a monitor and keyboard back at your desk. HP has yet to announce pricing for these accessories. In the spring, customers will be able to pick up the Productivity Jacket, which features a keyboard, SD Card reader, and additional ports.

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During our hands-on time, the ElitePad 900 snapped easily into the Expansion Jacket, but added significantly to the weight and thickness of the tablet, which is just 0.36 inches thick. The Expansion Jacket also comes apart in two pieces, so we imagine that once you snap everything into place, you're going to leave it there.

What about the rest of the specs? The ElitePad 900 has a front-facing 1080p camera--great for Skype video chats--and an 8-MP rear camera. Connectivity options include 802.11a/b/g/n Wi-Fi, Bluetooth 4.0, an HSPA+ module, and NFC.  HP BIOS protection, Security Manager, Drive Encryption, Computrace, and SpareKey are on board for protecting your data.

The ElitePad isn't a Windows 8 tablet for the masses like the Envy x2. HP designed this device explicitly to appeal to business customers, and it could very well cause companies to think twice about the iPad. We'll just have to see how well this slate performs and how practical (and affordable) the expansion options are.

Editors' Note: In our hands-on video we say that the ElitePad 900 will cost $699, but we have been told that final pricing is still being finalized.