I don't think that's what these forums should be about - just band talk. That would definately lead to a finite # of topics to discuss - you'd find yourself rehashing old crap with new words.
I also think there has been plenty of Opeth talk on this forum, but this forum really displays the type of person that is the Opeth listener. This has been said many times, but the intellectual level here is not equalled on any other board I've ever been on. It's what makes this a unique experience, and one I hope will not go away.
Based on many of these threads, the topics are deep, and sometimes I feel people feel free to tell people here things they would otherwise keep to themselves. Also, there is a minimum of that 4-letter word mentality found on most other boards.
If I was told to talk about Opeth only, I would still come here, but a hell of a lot less.