Laura Ries posted a copy of an article on convergence. It originally appeared in the Financial Times, but requires a paid subscription to view it there.
Laura's father, Al Ries, wrote the article. Al Ries is a renowned marketing expert that has written many books, including Marketing Warfare, Positioning: The Battle for Your Mind, and The 22 Immutable Laws of Marketing: Violate Them at Your Own Risk (each co-authored by Jack Trout). He more recently has co-authored some books with his daughter.
"Convergence" is the notion that product categories tend to merge rather than divide into separate categories. An example is all of the recent talk about computers and media devices combining. Al Ries firmly contends that the opposite is true - product categories tend to diverge.