I disagree. Both Lou Mongello (WDW Radio Show podcast) and Paul Barrie (A Window to the Magic podcast) have tried to do cruises in the past with Disney legends. Due to scheduling conflicts, I think Lou's cruise a couple years ago couldn't get the special guest, and due to the economy, Paul's cruise scheduled for later this month was canceled, but the land portion is going on the last weekend of this month.
Both cruises were planned before podcast cruise 1.0 left port.
However,
I'm sure by now a lot of people realize how successful the DIS cruise was and want a piece of the action. I'm not opposed to going on cruises with other communities, because the truth is, there is a LOT of overlapping in communities.
Before I got heavily into the DIS, I was pretty much into the RADP newsgroup and still have friends I met through them. I have a small contingent of Prodigy friends from WAY back, as well. And many of them have gone on to hosting sites and podcasts of their own, so I think the big family goes beyond the DIS.
If we're one big family, then the other overlapping communities are cousins.