If statistics and trends interest you, then click, don't walk, over to the Class Action Defense Blog. As a regular feature, Class Action Defense Blog summarizes (with self-described "unofficial" data) the number and type of class action filings in the major metropolitan centers of California. Their April 19, 2008 post is good example of the type of summary you will find on the site. In reviewing the numbers for at least 2008, it should come as little surprise to most class action practitioners that wage & hour class actions habitually hold sway with the largest percentage of filings by claim type.
Class Action Defense Blog is unashamedly and openly a firm-sponsored blog of Jeffer, Mangels, Butler & Marmaro, LLP, so it understandably tends towards a staid tone in its posts (I, on the other hand, having no restraining guidance behind me, am a loose cannon that could go off at any time). That blog is, nevertheless, dense with information about results and transactions in class actions around the country.