Google.co.uk does not yet have Search+.
However, some Search+ like effects have started to appear in the SERPs today and they follow on from the "latest posts" rollout that started yesterday.
I don't have MoneySuperMarket in my Circles and yet, on Google.co.uk, when I search for [moneysupermarket] I trigger their latest posts to appear in the old ad space on the right.
Compare that to the same search on Google.com. Spot the difference? I have the option to add MoneySuperMarket to my Circles in .com. I don't have that in the .co.uk because Search+ hasn't integrated Google+ with Search over here yet. I don't have the personalised results suggestions at the very top of the page either.