You bet it does - and now with the release of Google + and Search Plus Your World, it means that social messaging and the opinions of an individual's network will have an increasingly greater impact on your customer's search results.
Think of it as something from your daily life. If something is good, then you're going to talk about it. If you're talking about it, people need to know about it. With the current SEO model, the best optimized pages garner the most attention - but does that mean that those products are the best? Or that the service is the best? Of course not.
This is where Google comes in. By collecting all of that social data out there (tweets, comments, likes, +'s), Google will know who is talking about what - thereby bringing us, content that is relevant.
So how does a business (or individual) make their website king in this new SEO reality?
Well it wouldn't hurt to set yourself up with a Google+ profile. Considering that the new Google search plus your world does not include Twitter or Facebook, it looks like if you want to be considered by Google, you'll have to set one up - and start being included in some influential circles while you're at it. (hmm... was Google planning this the whole time?).
A word of caution - don't get caught up in the new Google Search reality and forget all the great things you already know:
- Without good content, you are just whistling Dixie
- Once you have that content, make it shareable and commentable
- Be a good friend: share content that you find to be valuable and give props where they are deserved
- Talk to people, learn from them, share what you know, build relationships