The most interesting part of Google+ that I've seen so far, is the "Huddle" feature. Although Facebook has its own Facebook chat, Google's Huddle is far more advance. The reason I think Google+ will really be a dominant force is because of the fact that their mobile applications are far more developed than any Facebook App I have used yet. The huddle is going to be an ideal alternative to texting, and will definitely surpass Facebook's chat in the functionality.
Although I do not believe this will be a quick battle, it's going to be a long war between Facebook and Google+ considering that Google has a long way to catch up to Facebook's stronghold on the market. But, if Google can stay one step ahead of Facebook throughout, I believe there is a shot. Google+ also will be tied with a lot of other Google Apps, and can become more useful considering everything that Google can tie into their Google+ project. I think it should be interesting to see what happens though.
As for Google's +1 button, I actually don't know how I feel about that affecting my search results. Although I'm very close with many of my friends, I may not like the same movie, or same restaurants as them and realistically I would not like that to change my search results.