When we reviewed Windows Phone a year ago, we liked a lot of what we saw, but recognized that it had more than a few gaps and rough edges. While the platform has attracted developers and applications, with more than 30,000 titles in the app store, success with consumers has been harder to come by. Though there are signs that the platform is at least appearing on buyers' radars, actual sales remain low.

Windows Phone 7.0 was not a perfect release. Desirable features—chief among them copy-and-paste and multitasking—were missing. It had an SDK and a development environment that were easy to use but narrow in scope; applications couldn't access the camera and were limited in the network connections they could make, for example. The release of the first upgrade, which added copy-and-paste, was anything but smooth, with delays, incompatibilities, and even the occasional bricked phone. Living with Windows Phone in the first year of its release meant living with some compromises.

A new approach

But there were pay-offs to be had. Windows Phone boasted a fresh and clean user interface that unapologetically avoided the look and interface of other smartphone platforms; Microsoft made sure that Windows Phone didn't have the aesthetic of a mere iOS knock-off.

More fundamentally, Windows Phone's interface was not built to be just another application launcher. Where the iPhone makes you dip into a host of applications—your contacts are in one app, their Facebook updates are in another, and their Tweets in a third—Windows Phone's concept is to combine the data from different services in ways that make sense.

So, for example, Windows Phone doesn't have an address book. What it has instead is the People hub. The People hub offers an integrated view of all your contacts (whether they come from Facebook, Windows Live, Exchange, Gmail, or Yahoo!), but it goes beyond the straight address book concept by incorporating social networking updates. It isn't just the place you go to find someone's phone number; it's where you go to find out what your friends are doing.

The same is true of the Pictures hub. Yes, your camera roll is there, but you can also manage pictures shared on Facebook or SkyDrive, you can see pictures your friends have taken, and you can see who's tagged you in photographic acts of drunken idiocy.

Some promises, unfortunately, weren't really delivered upon. We were promised hardware diversity (something offered by Android but not the iPhone) combined with timely, reliable, universal access to updates (something offered by the iPhone but not by Android). In the end, we got a little of both, though update delivery fell short of expectations with both fewer updates (only one feature update was made prior to Mango's release) and poor availability of those updates (the NoDo update was made available to everyone eventually, but it took months longer than it should have).

The interface and its underlying concepts made Windows Phone something different from iOS or Android. But the functional gaps meant that Windows Phone wasn't really better overall than iOS or Android.

Enter Mango

Windows Phone 7.5 "Mango," the first major update to the platform, is now out. It's Microsoft's big opportunity to turn things around, a chance to ensure that Windows Phone is as good or better than the competition across the board. The company claims the new version has more than 500 new features; while we're not quite sure about that number, it's certainly a substantial update for users and developers alike.

With the Mango release, Microsoft needs to do several things. On the software front, there are two priorities. First, Mango needs to remove the "buts"—fill in the gaps so that WinPhone recommendations can be unqualified. Second, it needs to consolidate the existing Windows Phone advantages—the slick user interface, the hub system, the integration and aggregation of data.

Software alone isn't enough to fuel demand for Windows Phone, however. Having the right hardware is essential. This doesn't mean that the hardware necessarily needs to be cutting edge, but it does need to be desirable. Microsoft needs good-looking, eye-catching phones that people aspire to owning.

Finally, Microsoft needs to market the product well. Windows Phone isn't an iOS knock-off, and that's a good thing, but it's also a thing that needs explaining. Buyers need to know how Windows Phone is different and why they should care. Dumb icons and silos of data are the smartphone norm; Microsoft needs to show people that there is a different way. And that it can be a better way.

Filling the gaps

Multitasking, copy-and-paste, tethering, a better browser, applications—those were the notable omissions when Windows Phone launched last year. Copy-and-paste was introduced in the NoDo update, leaving multitasking, tethering, a better browser, and applications as the "big" features that techies and early adopters look for. The actual importance of multitasking and tethering day-to-day is a little questionable; the iPhone for a long time had neither, and it did little to diminish its appeal.

But they have an importance beyond their day-to-day utility. The kind of people that care about these features are the same people who will adopt new technology early and advocate it widely to their friends, colleagues, and family. In many cases, they're the kind of people who fill out star ratings and feedback forms on the Web, or who blog about their latest gadget. By ensuring that the feature checkboxes are all filled, Microsoft ensures two things—that these people are willing to give the product a shot, and that they don't have to qualify their recommendations. It puts an end to "Windows Phone is good, but it can't do this, or that, or the other thing."

Mango takes them all on.