The Syncapse Measurement Science team put together an experiment on sentiment analysis, as applied to social media measurement.
As promised:
Link to the White Paper:
Link to the Data Set:
The Geurilla Analytics Project _ Sentiment
The paper will speak for itself.
We can discuss it here and on Twitter.

[...] previous study, published in this space, expressed dissatisfaction with standard sentiment analysis. My mind has since turned to the difficulty in expressing massive amounts of WOM into simple [...]