Honestly, I am not quite sure what this will turn into. I've seen hundreds of buzz monitoring tools, I've written some stuff in the past to do data mining of this type of information.
I am thinking why not build something with a front end as well?
What I am planning:
1. Pull data from Twitter about pre-defined keywords (Brands)
2. Run Sentiment Analysis
3. Graph over time
#. Maybe put mashup other data (stock price)
How this makes money? Probably doesn't right away. Licensing the code, building something more complex/target a niche for a later version. Use it to build credibility to sell other services.