When you ask a software person about coupling, they will usually tell you that it comes in two flavors: loose and tight. Other developers will tell you that it comes in 5 flavors (Data, Stamp, Control, Common and Content). Doug Kaye, will likely tell you that coupling is a continuum based on attributes. I believe they are all right - and that is part of my problem.
The art of coupling will likely rise to be the single most important design factor in the Service Oriented Enterprise. Unfortunately, the art of coupling (and cohesion) remains rather primitive. I think that we all would agree that Doug's recent effort to identify categories of coupling attributes was a great start. And by cruising other blogs, it is apparent that others have improved on some of his concepts.
As we approach a new year, it seems like an appropriate challenge to Doug (and friends) to create a coupling rating system. I'm aware that some of this exists in the academic settings (mostly on cohesion), but it is time to bring it to the masses. I'll gladly lend a hand and I'm sure that our Loosely Coupled community will chip in as well. And all good things take time - I propose that we iterate through it a few times, let it linger, demolish, rebuild and on January 1st of 2004 we publish a 1.0 of a new coupling rating system.