This article is very informative about CBM. The biggest issue CBM producers are facing is the dispose of Produced Water, which is a huge environmental concern.
http://www.energyjustice.net/naturalgas/cbm/
Many of the natural gas producers and coal miners have already involved in CBM exploration. Encana is the largest CBM producer in Canada. Apache, Trident Exploration Corp, Quicksilver Resources Inc, and other companies mentioned in this article are involved in CBM exploration.
http://www.tridentexploration.ca/DisplayLink.asp?LinkID=44
Raymond James also started to cover 3 Canadian junior CBM producers, they are:
Cordero Energy (COR-T) and Ember Resources (EBR-T), and Mahalo Energy (CBM-T)
BG (British Gas) offered to buy Origin Energy, Australia largest coal-bed methane producer, for $13B last month.
Please let me know your conclusions. :-)