Google has just announced on its official blog nine improvements to Google+, including some fairly major ones. For those into Google+'s Hangouts, you'll now be able to participate in them on your cellphone, if your phone is an Android 2.3+ device with a front-facing camera, though Google promises iOS support is coming soon. Additionally, they've added a feature called Hangouts on Air, which isn't a "hangout" at all so much as it is a broadcast meant for a larger audience, with a limited number of "broadcasters" enabled to start with (and we're willing to bet that one of those lucky few will be Robert Scoble, an avid Google+ user). Hangouts have also gotten a few other extra useful features such as screensharing, a sketchpad for doodling, Google Docs support, and the ability to name Hangouts.
Google has also released a basic set of APIs for Google+, and, best of all, opened the service up to everyone with a Google account.
Source: Official Google Blog