Google has obviously been pushing the use of the +1 button since it can indeed be a very good indicator of the relevance and popularity of a page’s content. Still we have yet to see just how much the +1 button will affect page’s in terms of overall page rank.
I personally have been using it more since Google Plus launched, but honestly have not really been taking the time to +1 all the pages I’ve visited and landed onto organically. This should be so, since the +1 button is not just about making your presence felt on every page you visit, but about “voting” for pages that have content you really like.
If you are interested in following the latest developments about the +1 button, you should definitely sign up for Google+ Platform Preview. Signing up will allow you to preview and test the latest updates to the +1 platform, including the +1 button, even before they are launched to the public. The Google+ Platform Review is available globally so you shouldn’t have a problem signing up for it. Remember, in SEO it’s about being on top of the latest developments in search, and what better way to do that than to test the very features that Google’s keen on releasing before they actually come out?