Lost amid all the smart phone hoopla is that these tiny, powerful devices are, well, phones. But that makes sense, because people are using smart phones for a lot more than making phone calls. They're essentially mini, connected PCs, with apps and access to online services, with local storage and beautiful screens, and interactive experiences. But with that said, Microsoft hasn't ignored the core phone capabilities in Windows Phone 7. It makes and receives phone calls. It includes integrated voicemail, speakerphone, call forwarding and call waiting capabilities, has an Airplane mode, integrates with hands-free Bluetooth headsets, and offers a wealth of ringer and vibration options too. It sends and receives text and MMS messages. And it does so in ways that are, naturally, very unique in a Windows Phone 7 kind of way.
Windows Phone's phone capabilities are exposed through two obvious UIs, the Phone application, through which you make and receive calls and access, and through the People hub, which is used for contacts management. Like other built-in phone capabilities, the phone functionality multitasks, so you can run it side-by-side with other applications (on capable networks, like AT&T's), allowing you to, say, talk on the phone while you browse the web or access some other application.
The live tile for the Phone application is dynamic, and provides the name of the wireless provider to which you're currently connected as well as, when needed, a number representing the number of missed calls and/or waiting voicemails. (They're combined, so if you missed one call and have one unheard voicemail, the tile will display a 2. But there is also a small tape icon that appears to denote that one of the waiting tasks is voicemail-based.)
The Phone tiles provides notifications about missed calls and voicemails.
The actual Phone app UI is pretty basic. It's a one-panel, single screen list-based application displaying your call history. In the App Bar, you can access buttons for voicemail, the virtual keypad, and the People hub (contacts list).
The Phone app.
Windows Phone has virtually all the phone features you'd ever need, with the possible exception of visual voicemail. There's a speakerphone, call muting, call hold, add call (essentially a way to switch between two live calls), and the like. When you receive a call, a pleasant overlay appears, either on the lock screen (if the phone is not currently in use) or at the top of the screen if you're already using the device.
Pop-up menus let you access other features while on a call.
The in-call overlay appears over the top of the screen during calls.
A nice full-screen overlay appears when the phone is locked and a call comes in.
From a Bluetooth perspective, Windows Phone hits all the high points, with support for Bluetooth 2.1 + EDR, the latest core Bluetooth specification, and the following Bluetooth profiles: Hands-Free Profile (HFP) 1.5 (for hands-free interfaces in automobiles), Headset Profile (HSP, for wireless headsets), Advanced Audio Distribution Profile (A2DP) 1.2 (high quality mono and stereo audio playback over Bluetooth), A/V Remote Control Profile (AVRCP) 1.0 (allows a Bluetooth device to be used as a remote control), and Phone Book Access Profile (PBAP, to exchange contacts data with other BT-compatible devices, like car kits). I've tested Windows Phone with a hands-free headset and it works as expected.
One minor disappointment is ringtones: Windows Phone includes several, and they're nice, but you can't add your own, at least not yet.
On the messaging (SMS, MMS) side, it's mostly good news. The Windows Phone Messaging client is attractive and functional, and it bundles all of your messages to individual contacts into separate conversations.
The live tile for Messaging is dynamic like that for Phone, and it will show a number of unread messages if there are any. The application itself is a single pane list, called Conversations, where messages are divvied up by contact. So you won't see multiple entries for the same contact, even if the conversations you've had with them occurred over time.
The Messaging app.
Sending and receiving messages is simple enough, and you can access the Messaging interface by using the Share option in many Windows Phone experiences. So if you want to share a photo, you can do so directly from the photo itself, and you don't need to navigate to the Messaging app first.
Sending a text message within a conversation.
If a new message arrives when the phone is locked and off, Windows Phone will play a notification sound and light up the screen, showing the lock screen. At the top of this screen, you'll see a notification toast, or overlay, displaying the text part of the message and who sent it. If you are doing something else with the phone when a message arrives, Windows Phone will again play a notification sound, and will again display the notification toast, overlaid on top of whatever screen you're currently viewing. In this case, the toast is interactive: If you tap the overlay, Windows Phone will navigate directly into the correct conversation in Messaging. It's a nice touch.
Windows Phone does have some limitations when it comes to MMS-type messages. For example, though you can take videos with the device's built-in camera, Windows Phone does not support the sending of videos via MMS. Likewise, there's no way to send audio files via MMS either. (You can receive them.)
Overall, the phone and messaging capabilities are as expected. They're not exceptional, and much better than the competition, but they're not worse either. This isn't a reason to get--or skip out on--Windows Phone. But that's just fine.