Coruscation

Mango still offers everything that Windows Phone already had going for it: a terrific onscreen keyboard with smart auto-suggestions. Integration with your Xbox account. Microsoft's Zune music service ($15 a month for all the music you want to hear). A GPS app that now speaks your directions, turn by turn.

Now, if this phone had arrived before the iPhone, people would have been sacrificing small animals to it.

But Microsoft's three-year lag behind its rivals is going to be very tough to overcome.

Windows Phone is considered a weird outlier. Unlike with the iPhone, there's no teeming universe of alarm clocks, chargers, accessories and cars that fit these phones.

Similarly, Windows Phone's app store has 30,000 apps, which is an achievement -- but Android offers 10 times as many, and the iPhone store has 16 times as many.

Microsoft says that it's quality, not quantity, and that all the important apps are there. Unfortunately, a long list of essentials are still unavailable: Pandora radio, Dragon dictation, Line2, Flight Track Pro, Ocarina, Instagram, Hipstamatic. You should note, too, that Microsoft's schoolyard grudge against Google manifests itself in several disappointing ways: you can't export your videos to YouTube, and you can't search with Google.

In other words, Microsoft may face quite a Catch-22, no matter how superb its work: Windows Phone isn't popular because it isn't popular.