Well this has come at the right time for me! I’ve only recently switched my main site here over to HTTPS completely. As I was doing it I kind of hoped Google would at some stage think about ranking fully secure sites a bit higher in an effort to cut out poor or insecure sites from results but didn’t think they’d be so quick to implement it.
While being fully HTTPS isn’t a massive ranking factor at the minute, it may get more important over the next few years so I’d recommend getting a secure cert for your site now. Here’s the full Google announcement re HTTPS ranking:
http://www.googlewebmastercentral.blogspot.ch/2014/08/https-as-ranking-signal.html
I can help with the setup and a secure cert only costs about €15 per year.
Leon