Microsoft have previously stated that one of the 500 features coming to the "Mango" Windows 7 Phone platform is "visual voicemail," that allows the user to visually see messages that people have recorded and has numerous options available that previously could only be done by telephoning a specific service.
As it turns out, when you have voicemail messages waiting and you tap your "phone" live tile, you'll see a "Voicemail" pivot along the same axis as the call history. In the Voicemail section you'll see the names of callers along with the day and time that they had left a message along with a play button right next to their names. Listening to each message is obvious - just press the play button. At the bottom you can turn on the louder rear speaker as well as turn on a multiple selection mode for deleting messages. In the call settings, there's a "Visual Voicemail" on/off toggle switch as well.
Mango's visual voicemail support makes checking voice messages so much easier since you no longer have to dial in, enter your passcode, and wait for the recordings to tell you all the instructions and whatnot before you can get your messages.
Pocketnow has released a video walkthrough of the functionality which can be found by tapping the phone tile, with the voicemail 'pivot' being selectable from the options at the top. If you're using WP, you'll now notice that the voicemail option which was previously located at the bottom of the phone screen, is no longer there.