Windows Phone 7 updates codenamed Tango and Apollo?

If you were wondering about what the next version of Windows Phone 7 will be after the Mango update drops, the folks over at DigiTimes seem to have the answer. The industry insider recently reported that the update following Mango will be codenamed Tango, and the one after that will be called Apollo. Apparently Microsoft has already started working on the updates.

Since Microsoft hasn’t made any mention of Tango before, we’ve got no idea what the update will bring. The choice of codename also poses some interesting questions – is there some sort of pattern that Microsoft follows when naming its operating system updates? Can anybody detect a pattern in the names?