Yesterday afternoon (Friday 04/02/10), I checked Ammonia again, still 0, so I really think the seed worked well as an almost instant cycle. The filter was removed from my kid’s well stocked tank and hooked up to new tank, and fish introduced, within 45 mins. I hear that the bacteria may survive without fish for a day or two, but I don’t know how accurate that info it. I didn't want to risk it and certainly 45 mins is a fast switch out, so I think anything that had colonized the filter certainly survived, plus the fish waste has managed to keep it alive.
I had to cull one of the cherry barbs on Friday, one that would not have made it until Monday I think. Others are very active, playful, and seem to really enjoy the 75 gallon, even though it is amazing bare.
I just picked up a few more cherry barbs, and I'm acclimating them now.