Right now, no. But in the future it's very likely. My site has over 1k +1's on it so far, so it better help.
Google+ has same use as facebook's like button. The post/article that gets +1ed is promoted in friend list/circles and thus your website may attract traffic from social media websites like Google+. Same thing happens when your posts get recommended on facebook.com or tweeted etc. Currently, it is believed that Google is measuring the popularity of a website in social media websites (including G+ and others) and using this as one of the factors to rank websites in SERPs. However, the biggest factor affecting ranking is bounce rate and time spent by visitor on landing page of website. Another use of G+ is that people following you will see LPs from your website rank higher.
At this time as I think there is little effect, but who knows what is the plan (I mean - how Google is going to use it)