Google+ Comments for Blogger is already out. Those of you who are passionate about making your website more Google+ friendly surely appreciate this new system by Google. You will have to wait a while to get your hands on G+ comments for WordPress though. There is no official plugin out. The good news is developers such as Brandon Holtsclaw have already made the system available for WordPress.
G+ Comments for WordPress could be soon available through WordPress. It remains to be seen when it gets approved. It also does not have all the features yet but remains a work in progress. The good news is as people try it, the developer will learn about how this could be improved. You can download your copy here.