Windows Phone 7 is not an iPhone killer—but in reality, no mobile operating system is. Windows Phone 7 may not even be an alternative to the iPhone, given that many Windows Phone 7 handsets cost the same as the iPhone. Rather, Windows Phone 7 could be—and should be—viewed as a distinctive smartphone platform that’s leveled at a different audience. While there are many overlapping features and functionalities between Windows Phone 7 and iOS 4, making the decision between a smartphone running Microsoft’s Windows Phone 7 or Apple’s iOS 4 will largely depend on what it does or doesn’t do, versus what it does better or worse than the iPhone. With that in mind, let’s walk through some of the key differentiators between WP7 and iOS 4.

Interface and Home Screen

Other reviewers may disagree, but from my experience, I believe the difference between WP7 and iOS 4 lies in its focus. WP7 is heavily focused on people, while iOS 4 is very app-centric. This is made most apparent in the way that WP7 handles your contacts. It consciously avoids assigning treating phone numbers, email addresses and social media profiles separately. Instead, it lumps all of this contact information together (either by linking or by creating a single unified contact) and allows you to pin that contact to your Start screen. This contact is wired together with everything—you’ll not only see their phone number and email address, but you’ll also see their latest Facebook updates and photos.

iOS 4, on the other hand, doesn’t keep contacts front and center. In fact, save for a few bookmarks that can be saved to the Home Screen, iOS 4’s home screen is dedicated solely to apps. Facebook integration isn’t baked in to the operating system—rather, the social media connectivity and messaging beyond text and email is left up to third-party apps.

How this factors in to your smartphone use depends on how you use social media. Do you use social media to keep in touch, or mostly for browsing? If you regularly use social media to communicate with certain contacts, the Windows Phone 7 may be a more seamless solution.

Office and Productivity

Windows Phone 7 has Office, the iPhone doesn’t. That’s all there is to it. Windows Phone 7 come with mobile Office, which features editing, viewing, creation, syncing and sharing of Word, Excel and OneNote documents and viewing of PowerPoint presentations. Hands down, the Windows Phone does mobile Office best. You can get third-party apps on other platforms, but the experience won’t be nearly as intuitive or functional.

If you want to do serious business on your phone, get a WP7 phone. If you just use your smartphone for jotting down grocery lists and reminders, any other smartphone (or feature phone) will do.

Cloud Services and Market
The iPhone and WP7 both have their associated cloud services and marketplaces for downloading apps, games, music and podcasts. With the iPhone, you can sync your contacts and other files via MobileMe. You purchase songs and podcasts through iTunes and apps through the App Store. With Windows Phone 7, the experience comes through the Windows Live suite, which includes your SkyDrive, Windows Live Messenger and Windows Live Mail (Hotmail). You purchase games, music and apps through the Marketplace—plus you have access to the Microsoft Zune Pass.

Which is better? That depends on what you already use. If you already use an Apple account for your iPad or iPod, it makes sense to keep it consistent with an iPhone. If you’re a heavy Windows Live user or enjoy a Zune Pass, then a Windows Phone 7 will be an excellent complement

Other Features

Windows Phone 7 doesn’t have copy and paste or multitasking—yet. This may be a dealbreaker for you, but copy and paste is reportedly coming with the next update. Plus, neither Windows Phone 7 nor iOS 4 has true multi-tasking, as you’ll see on Android phones or Symbian phones. Both of them do use saved and restored states and limited backgrounding, but iOS 4 has wider support for third-party backgrounding than Windows Phone 7. This is important for programs like Pandora and Rhapsody.

Overall, the iPhone does feel slicker. Its menus are beautiful and most of the apps are well-designed, smooth and stable. And like all Apple products, there’s much that seems to “just work” without any hassle. But if you’re in anyway married to Microsoft products—such as SharePoint, Outlook or Office (the first two of which weren’t discussed at length, but are supported by WP7), then a Windows Phone 7 is going to make the most sense for you.