Google have just announced an extension to the social media reporting in Google Analytics - http://analytics.blogspot.com/2012/03/capturing-value-of-social-media-using.html
These new reports open new ground to social media marketers looking to get an idea on how much money their efforts are making for a website (but only for those social networks that play ball with Google - see later)
The first new report looks at the multi-touch nature of a social media conversion. Its common sense that social media works higher up the sales funnel - its value is more in raising awareness of your brand and product rather than in direct sales (at least, that's how a lot of social media advocates sell it)

The new GA reports look to give you an idea on that effect. Using three circles, it shows you:
The real value of social media now has bounds - it should lie in-between the middle and lower figure (if all social media networks play ball....still see later)
Social segment graphs are also available to compare your social traffic conversions to the rest of your website. A particularly good viral uplift in social should be easier now to track to later bumps in conversions through other means.

These reports work by looking at the referrals for your visitors, and grouping all social media websites in a channel group. This kind of segmentation was previously available via the multi-channel reports, but only with a look back of 30days.
Use: Quick overview on how social media is contributing to your bottom line goals.
This all works with no additional tagging, unlike the social plugin reports http://support.google.com/analytics/bin/answer.py?hl=en&topic=1316551&answer=1316556 that have been moved to the new GA social section. These social actions reports require tagging up of your social network buttons on your website to make them appear correctly - unless you have G+ in which case this is all taken care of behind the scenes.
Use: Showing how effective your content strategy is working in being shared
This is the real game-changer. Now GA is for the first time offering you information from off your website to help you judge performance. For those social networks participating in Google's Social Hub programme http://code.google.com/apis/analytics/docs/socialData/home.html (including Reddit, Delicious, Blogger and of course G+) you can assess and read discussions for users talking about your website even if they do not click through. This is huge, and shows the drift towards a web-holistic approach modern internet marketing is becoming. Knowing the data for just your website is not enough, as your public face is every user contribution talking about you as well.
The notable exceptions in this are Facebook and Twitter. Without their participation, how accurate can these reports be? Could it be that with the increased transparency the new GA reports will show that they will need to step up and offer their own social analytics systems to the same standard? Or will they roll over and participate in the Google social Hub initiative, since in the long run it will mean marketers spending more on their product?
Use: Showing what content performs well off your website - does content A work better on G+ or Reddit?
And could this transparency actually show that, in fact, not many people are influenced by social media for buying things? That things are bought not because all your peers have them, but because they fit in your particular lifestyle? In which case, should social media marketing move instead to dissecting all the information users put into networks themselves which hint at buying patterns, rather than their social graph? And where will privacy fall into this? These are all answers which now look to be able to be answered.