http://www.halfaya.org/dorama/renzoku.html
John Leo wrote this paper back in 1997. I fell upon it while doing some research myself. Very interesting reading... It covers many aspects of Japanese dramas, including OSTs, romance themes, and great comparisons between Japanese and American TV programming. It answered many of my questions about why things are what they are in the Jdorama culture.
Here's one really interesting quote from the paper regarding opening credits:
The opening title sequence of a dorama ("opening" hereafter), a short segment with the cast and staff credits, has become something of an art form itself over the years. In the US, the opening has mostly disappeared from sitcoms; for example a few years ago the head of ABC banned openings from shows, fearing the audience would change channels during the opening. In contrast the opening continues to be a major element of dorama.
--- groink