Acer only confirmed it was a partner in Windows Phone 7 just a short time back, but already, it has a Windows Phone 7 handset in a seemingly finished state, going by the name of the Acer W4. Not only that, it's already got the Mango update of the operating system on board.According to Pocket-lint, the phone was spotted at the Computex trade event in Taipei, Taiwan. In fact, not only has the phone been shown off, the specification list has also got an airing too. All neatly laid out on a piece of card at the side, in fact. The perfect product leak, you could say.According to that card, the new device will have a 3.6-inch 800x480 capactive touch-screen, up to 8GB of in-built storage, a five-megapixel camera with auto-focus, Qualcomm MSM 8255 1GHz processor, DLNA, Wi-Fi and Bluetooth 2.1. Oh yes, not to mention that Mango flavour of Windows Phone 7.Sadly, no one bothered to shoot a hands-on video, so we don't know if it was a dummy model or a working handset. Either way, it's real and likely to be here when Mango lands, which is around autumn.