SAN FRANCISCO – The next Android operating system for smartphones will include some features that were previously exclusive to Android tablets, Google announced Tuesday.

Dubbed "Ice Cream Sandwich," the platform will debut some time in the fourth quarter of 2011, Google officials said during the company's I/O developer conference.

"We want one OS that runs everywhere," Android engineer Mike Claren said at the conference.

Ice Cream Sandwich-powered smartphones will ship with enhancements introduced in Android Honeycomb, Google's operating system for tablets. Some of these new features include a holographic user interface, enhanced multitasking abilities and the ability to connect the smartphone with a USB device, such as a mouse or an Xbox controller.

The release of Ice Cream Sandwich has been highly anticipated by the Android developer community. Android version 3.0 (Honeycomb) first debuted on Motorola’s Xoom tablet in February, touting a host of enhancements and features new to the Android platform. Developers have been waiting for Google to release the Honeycomb source code, in order to bring some of these features to smartphones.

So far, Google has refused to do so. After a long period of silence and a whole lot of fear, uncertainty and doubt, Google issued a statement to members of the press in March: “While we’re excited to offer these new features to Android tablets, we have more work to do before we can deliver them to other device types including phones. Until then, we've decided not to release Honeycomb to open source.”

Google Chairman Eric Schmidt’s February comments at the Mobile World Congress in Barcelona shed light on why the company was holding out. Schmidt said that features from Gingerbread – the most recent software release for Android smartphones – and features from the tablet-optimized Honeycomb software would be combined in the next iteration of Android.

"Google is making sure that the OEMs [original equipment manufacturers], who are all desperate to differentiate their products, won't take the Honeycomb source code and slap it on a bunch of bad products," Gartner Research analyst Ken Dulaney told Wired.com in an interview. "The bottom line is, this is the right way to do it."

The Android platform has been incredibly popular since its debut in 2008. To date, over 4.5 billion apps from the Android Market have been installed, according to Hugo Barra, director of Android Product Management. Today, Barra said, the Android Market officially has over 200,000 apps.

To tide over those eager for a new version of Android, Google will be rolling out a new version of its Honeycomb software, version 3.1, over the next few weeks. Owners of Verizon's Motorola Xoom tablet will be the first to receive the new software.