So far at MIX 2010, a lot of new Windows Phone 7 Series features have been shown off. One of the most basic functions of a phone is the ability to actually use it as a phone. Joe Belfiore attempted to recieve a call during a demo, but instead had to settle for placing one. The call pops up over the current screen, dimming what's in the background. It's unclear, from what he showed, if you can continue what you're doing while on a phone call. He does note that when making phone calls, the name of the person is "hot." This allows you to tap someones name and select alternate ways to communicate with them.
Belfiore also showed off searching with Bing and how WP7S delivers your searches based on what you'd logically need at the time. Remember, Bing is a decision engine. You can still see some flaws in the UI layout, like where the Bing search bar covers over the battery meter (seen in video below). But, keep in mind, the OS is still not complete.
Texting hasn't been showcased much until MIX. WP7S will support both SMS and MMS. The on-screen keyboard is an interesting animal. Text recognition and correction works differently than on other smartphones. If you notice a spelling mistake after finishing a message, you can click a word, which highlights it, and then select a word to replace it with from a list that comes up.
Not much new was shown regarding the Games Hub. There's a section called Spotlight which shows you new games, as well as tips about games. The one interesting thing shown was the Requests section. On your start-screen, you will sometimes see a number in your Xbox Live tile. This symbolizes invites to play games, as well as notifications of actions for you to take (such as make your move in a game of chess).
When it comes to syncing with your PC, the Zune software is going to be your primary tool. It's sleek, sexy, and works very well. However, we're talking about a phone here, so there's gotta be something else available besides basic, tethered syncing. Most people in the world never end up moving their pictures from their phones to PCs. Microsoft sees this as a problem. To rectify this, a WP7S device, when plugged into power, will sense if it's connected to your home network, and automatically begin uploading your photos to your PC. This ensures that you never lose anything, and are also able to utilize those pictures in a non mobile environment.