Windows Phone 7.5 is starting to roll out today to Windows mobile phones around the world.

The first major release since Windows Phone 7 launched less than a year ago, the 7.5 release offers hundreds of new features and experiences designed to build on the phone’s intuitive, “people-first” foundation – multitasking, more integrated apps, primo mobile Web browsing, and powerful and personalized tools, like integrated social networking and conversation threads, for connecting with people.

“One of the things I’m most proud about with Windows Phone is that we took a different approach,” says Andy Lees, president of Microsoft’s Windows Phone Division. “We looked around and saw that smartphones were largely becoming application launchers, and consumers were left to navigate a sea of icons and a grid of apps. We looked to build all the core things that consumers want to do directly into the phone, and focus it all around people – not icons.”

The update will be gradually rolled out to existing Windows Phone owners and will be pre-loaded on to a number of new phones.

Microsoft’s goal is to make the update available to 98% of phone customers worldwide within four weeks.

IDC predicts that Windows Phone will defend a number two rank and have more than 20% of the smartphone market by 2015.

“With Windows Phone 7, our goal was to build a phone we could be proud of and that consumers would love. I think we surprised a lot of people,” Lees says.

The phone also continues to integrate Microsoft services, including Bing, Office, Xbox LIVE, Internet Explorer and Windows Live.

A new Groups feature lets consumers create groups from their contacts – think trivia buddies, soccer teammates, coworkers or family – and turn them into a personalized Live Tile on the Start screen. From there, people can use the feature to quickly contact everyone, or to see communications received from people in that group whether it’s a call, a text or an email. They also can see the social updates and photos solely from that group of people.

In the People Hub, the What’s New? feature now shows updates from Twitter and LinkedIn in addition to Facebook and Windows Live, in one easily filtered social network feed. An updated Me Tile on the Start screen shows social notifications – one tap lets consumers see when people mention them in a Tweet or interact with them on Facebook. From there, another tap will take people directly to that post where they can “like” or comment on it.

The 7.5 update also features intelligent multi-tasking so people can quickly switch from one app to the next without affecting battery life or performance. For example, consumers can switch from a game they’re playing to check email or play music, and then return to the game and have it resume instantly, exactly in the place where they left off. The update also sports Internet Explorer 9. Lees said: “With Windows Phone 7.5, we move to having one of the best mobile browsers on the market today with Internet Explorer 9 – complete with hardware acceleration and the same rendering engine as the PC.”

New Bing integration includes Local Scout, a tool for finding both the expected and the unexpected nearby; Bing Vision, which lets people search with their camera and even translate text into different languages; and continued developments in voice recognition, allowing consumers to do hands-free searches and even texting.

“Windows Phone 7.5 offers a natural way of finding things and discovering things around you that is really powerful, like nothing else,” Lees says.

“Applications are fantastic because they extend the capability of the phone, but the problem is that applications today are locked up in silos. With Windows Phone 7.5, information inside of applications breaks free from their silos and comes directly to the Start screen through Live Tiles, or participates in our own experiences which we call Hubs.”

Customers can visit the People Hub to see updates from all their social networks, rather than having to visit each individual app. If someone wants to track the weather in two locations, they can create a Live Tile to track weather in multiple locations.

Windows Phone has about 30 000 apps in its marketplace, including 90 percent of the most popular titles available on leading competing platforms.

Some developers have already updated apps to take full advantage of the new Windows Phone 7.5 features such as multitasking and Live Tiles, including Flickster, foursquare, AllRecipes, and the game Parachute Panic.

The latest Windows Phone update also includes a feature called App Connect, which suggests helpful apps as people search or complete tasks on their phone. Search for a movie or an actor, and App Connect will suggest trying the Internet Movie Database (IMDB) app or Flixster, for example.