There is a free report from Martin Butler on Social Media Vendor Analytics.
Included in this brief report are profiles of eleven social media analytics solutions.
Alterian: Sophisticated offering suitable for medium to large organisations, with excellent sentiment analytics.
Brandwatch: High quality social data and good sentiment analysis tools.
Coremetrics: Very sophisticated solution with deep integration into IBM's WebSphere technologies.
IBM Social Media: Combination of services and solutions typically for large corporations.
Lithium: Enterprise level solution with strong collaboration features.
MutualMind: Closed loop model for quick conversion of information into action.
NM Incite: Top-end offering from Nielson and McKinsey. Many unique features - at a price.
Radian6: Very rich visual analysis environment - just been acquired by Salesforce.
SAS: Large, complex solution with opportunity to perform almost any kind of analysis.
SocialSprout: Easy to use - ideal for agencies, small businesses and individuals.
uberVU: Excellent all-round capability, providing a very cost effective solution.
Viralheat: Very sophisticated analytics for a very modest price.
Report available at http://www.martinbutlerresearch.com/social-media-analytics/