This is heading in the right direction, but I remain skeptical of the simple "you're connected to this person through some service (probably unconnected to the search query), so you trust them" symbol as the main recommendation symbol. This is one way Color actually interests me, they're exploring new symbols for connection, even if I think they're kind of weird and hard to understand at first glance.
I don't know how well this +1 thing will work, because as many others have noted, it's not passive. I have to actively click on it, and that's not something I think about when I'm running a search.
The you're connected to this person thing, however, has worked out quite well for me. A lot of the time, I'm looking for something that someone I follow on Twitter shared - and it just bubbles up for me. I'm a fan.
Won't know for sure until I try it though.