yer definetily worth to be on it and promote on it .. Google + will make the difference . You will see , so get on it and start promoting.... cheers
As of the moment you can get into Google+ through invites. If you know of someone who has an account then have them invite you. Google+ is actually a good social network that helps you easily organize your contacts through the Circles feature. It's also a good way to communicate with friends via the Hangout.
The new iddea that crss my mind . If you want to be indexed faster by Google search engine just Google + it. Think smart!!
Yes, it may be in the future. Currently you cannot just "sign up" however it is all based by invite only