Core77 recently made note of a discussion in their forums about just that: the Core77 forums. Who knew that they’d been around since 1998? (Though the proof only goes back to 2003). I sure didn’t.
Still, this is a entry into what appears to be a decline in online commentary relating to design. I suspect that the IXDA forum isn’t the hive of activity that it was when I joined in early 2007 (I remember spending the first half hour of each day reading the threads). A number of people on the Your Dreams My Nightmares podcast have suggested that the era of meaningful comment threads on sites such as Design Observer (or the illustration portfolio website Drawger) are over. Why? One word: twitter.