User interface: In terms of user interface, WP8 doesn't change anything. Just like the earlier versions of the software, WP8 looks beautiful with layered users interface, clean lines, and lots of square boxes - Microsoft calls them tiles - that replace program icons. These tiles, unlike icons, are bigger and can display nuggets of information. For example, the Mail tile can show the number of unread mails. The layers in the OS give the user interface a 2D effect. It is a very unique and modern design and works well. We tested WP8 with HTC 8X and found no lag or low frame rates in the user interface.
New lockscreen: The original Windows Phone had no notification system. It relied on live tiles to show new information to users. But WP8 has a lockscreen where six apps can show their notifications. However, compared to what competitors have in their mobile software, it is still basic. Apps can also use lockscreen as a canvas where they can show information or change content. For example, Bing app can refresh the lockscreen wallpaper to match it with whatever it is showing on its website.
Customizable homescreen: Previous versions of WP had an empty bar on right side of the homescreen. This, we believe, was added for design reasons as it gave the screen some depth and highlighted its 2D effect. But in WP8 it is gone. Now the live tiles can stretch across the screen and show more content. The tiles can also be resized as tiny small or big. This makes the homescreen on WP8 immensely customizable.
Rooms: This is a new feature that allows users to club their contacts together. Once a Room has been created with a few contacts, the users part of it can share calendar, chat room, videos and photos etc with ease.
Support for better hardware: With Windows Phone, Microsoft decides what sort of hardware its partners can put in the devices. Compared to the previous WP versions, WP8 supports better hardware, including dual-core processors, 720P resolution screen, better cameras and 1GB RAM. It also supports storage expansion through microSD cards, something that was not available to WP users earlier.
Kid's Corner: This is one of the signature features of WP8. It allows users to create a separate list of apps that restrict any kid using the phone to that list. This means, when your kid is playing Angry Birds on the phone, he can't go to your Twitter app, even accidentally. For people who don't share their phones with kids, this feature may not matter much. But those who do will appreciate the usefulness of it.