The Sony Ericsson Xperia X10 Android phone is real. After months of leaks, it’s finally broken cover officially, and while Sony Ericsson did a better job than most of keeping the name under wraps, the Google phone formerly known as the X3 is now out of the gates, with that gorgeous new UI in tow. Want to know exactly what it does? Read on for the deets.

On the hardware front, the Sony Ericsson Xperia X10 is pretty much the phone we’ve seen leaked for months. It’s got a 4-inch, capacitive touchscreen, eight megapixel camera, a superfast 1GHz Snapdragon processor, 3G and Wi-Fi, plus a microSD slot. Up close, it’s a gorgeous slab, if not quite as skinny as the HTC HD2.

The skin (codenamed Rachael, but nameless at the time of our briefing due to legal reasons and due diligence checking) for the Sony Ericsson Xperia X10 focuses around two signature applications, Timescape, and Mediascape. The former works like Motorola’s Motoblur, pulling in emails, texts, Facebook and Twitter into a reverse chronological stream. Touch a contact’s profile picture within it, and you can pull up all the relevant information around them. Messages, numbers, it’s all here. It’ll even drag in photos of them.

Mediascape on the Sony Ericsson Xperia X10 works just as we saw in the teaser video yesterday, aggregating your own music as well as recommendations from the PlayNow service (Sony Ericsson says mobile networks’ own music stores can plug themselves in here too, if they like).

There are a couple of truly classy touches in Mediascape too: pressing the “Infinite” button on the Sony Ericsson Xperia X10 while listening to music pulls up Youtube content related to the artist you’re listening to, while Sony Ericsson has also included face tagging, so you can shoot photos of someone once, and they’ll be automatically tagged in the future.

Sony Ericsson’s head of portfolio planning, Steve Walker, told us that this is just the start, and that in future we’ll see closer integration with other Sony products, though he wouldn’t comment as to whether the PS3 was a possibility, via Remote Play like the Sony Ericsson Aino.

Are there any downers to the Sony Ericsson Xperia X10? A few: it’s only running Android 1.6 rather than 2.0, although Sony Ericsson says it will move to tasty Android 2.0 “in time”, and there’s no multitouch for pinch zooming. Otherwise though, it’s shaping up to be a stonking phone, and more than a worthy entry into the world of Android for Sony Ericsson.

The Sony Ericsson Xperia X10 will be on sale in the first quarter of 2010, with network carriers still to be confirmed.