Yes the SH forums are great resources. I'm not sure if a whole book on the subject needs to be written, or if there is a broad market for the book.

That being said, I believe there does exist a reasonable market. A good idea might be to add significant sections (more detail than King Yao's and Jennifer Harmon's - Sklansky's too for that matter) to SSH for the very loose and aggressive small stakes games, and HEPFAP for the more advanced 5-6 max games.

This could be marketed for future editions, and I believe many that already own each book would buy the new edition (I would). The worst players are playing 6max online, but you can get your nose bloodied pretty quick if you don't know what you are doing. Money is there to be made for 2+2, or anyone else, that brings forward a defining piece on this subject. Maybe not as much as on other subjects, but money none the less.