@JPB,
Anytime you make changes (to GUI), it's bound to affect some members of the community. Could we be seeing a natural turnover in the community as we "mature" and the interface changes? I will let others comment on that.
Also there could be a macro phenomena going on. I see a lot of people that are feeling displaced (and grumpier?) now due to more severe economic pressures -- loss of jobs, loss of homes due to foreclosure, loss of financial reserves. Should we think that we as a community are isolated from this? Maybe I'm reaching a bit here...somehow this outside economic effect could be having some trickle- down effect on the dynamics here?
I feel that the welcoming of newbies contributes mightily to the community. It helps bring in new blood and possibly cement them (for awhile). It also gives a good feeling to the veterans that this IS a community not jasut a way of passing the idle hours. So why is it that I don't do it any more?
I can only speak of my own experience here about my own feelings of community. I generally don't see many comments made to me after any of my replies unless it's in the NFL contest threads. I have ceased to make new posts. I don't really know why, frankly. Perhaps, it's me, though. Perhaps I feel more anonymous and disconnected now then I did with other interface, but I may be digging too deeply and off base there.
Also, I think a component of the unwelcoming community problem is the testiness of the recently passed political "season." That should be a temporary effect, however. Or, is it?