Wow... this is EXACTLY(http://news.ycombinator.com/item?id=4177548) the thing I have been planning to work on in the last 4/5 months... Time to think of something else... I hope they will make a good job, I like Mixpanel.
A Competitive Density Matrix(http://www.khaitan.org/blog/2010/10/competitive-density-matr...) to size up your product against competitors will help.