Monday afternoon in Los Angeles, where the software giant has invited Mashable and a handful of other tech press.

Naturally, the speculation has been rampant, but it has also been relatively focused (Microsoft, a sprawling company not known for secrecy, may have had a hard time keeping the wraps on anything this big).

From the mouse to Xbox, Ballmer says, the best experience has been when software, hardware and peripherals work together. He quickly introduced the Surface tablet. Not Xbox Surface, just Microsoft Surface.

It’s got a 10.6-inch screen, thickness of 9.3mm, “just wide enough for a full-size USB,” says Windows chief Steven Sinofsky, who joined Ballmer to show off the goods.

The tablet is tough, with a Gorilla Glass 2.0 screen. Like iPads, it has a magnetically connecting case, but this “Touch Cover” actually has a full multi-touch keyboard, too.

The star of Microsoft’s mystery Monday unveiling has been revealed: Surface, a Windows tablet.

“It was always clear that what our software could do would require us to push hardware, sometimes where our partners hadn’t envisioned,” Microsoft CEO Steve Ballmer said at the event. “Much like Windows 1 needed the mouse, we wanted to give Windows 8 its own hardware.”

Just as Windows 8 is a reimagining of the Windows operating sytem, Microsoft describes Surface as a reimagining of the tablet.

The first of its kind, Surface is designed to work as both tablet and PC and comes in a version running Windows RT as well as a version running Windows 8 Pro.

Super-thin, the tablet is just 9.3mm thin for the Windows RT version and 13.5mm for the Pro version. Both have two full size USB ports — something you won’t find on the vast majority of the tablet competition. You’ll also find a Micro SD port on the side of the RT version and a microSDXC port of the Pro version for adding data to the device or reading files (like pictures from your digital camera) on the fly.

Surface has a 10.6-inch 16:9 widescreen HD Display screen. Designed to be mobile yet sturdy, the screen is made of Gorilla Glass -– an ultra-strong glass – to prevent scratches and breaks if it takes a tumble.

A built-in kickstand on the rear of the tablet holds it up while you’re typing or viewing videos.

A Touch Cover for the device protects the screen, and much like Apple’s Smart Cover does with the iPad, it connects to Surface via magnets on the device’s side. Unlike Apple’s cover, however, the inside of the 3mm cover doubles as a fully functional keyboard with a built-in trackpad when opened up.

Both versions of the tablet have 2×2 MIMO antennae. The RT version has a Micro HD Video port while the Pro version has a Mini DisplayPort Video.

After traveling from Seattle this morning, I hitched a ride from the airport with Wilson Rothman of msnbc.com and we’ve made our way L.A. to the site of Microsoft’s mystery event in Hollywood this afternoon, at Milk Studios.

An initial drive-by of the location didn’t reveal any secrets. Crews are busy loading audio and staging equipment through the rear entrance.

Stay tuned for live coverage from the event this afternoon. The doors open at 3:30 p.m., but no word yet on when the event actually gets going.