Right. I have to apologize, I was mistaken. It was not developed there, but hari announced it and his server there as well as on the forum. My bad. I was confused, as there were some mails going back and forth about the sqlCVS with the build-from-scratch-process.
I don't see it as setting up a bunch of new places, but daniel provided us with a full development area with svn, bugtracker trac and a mailinglist. The advantage is that these places at charonmedia are maintained. So I'd see the mailinglist as an addition.
To the three accounts: I guess you can forget about the mantis account. It seems somewhat useless. There are some people I have never heard of in the forum or wiki or mailinglist, that produce patches that I never got to see. That seems to be pluto-people with their system, but without feedback to a community-driven development, we're certainly all trying to achieve together...
In my opinion, the advantage of the mailinglist is, that you don't have to keep track of it. It comes to your inbox if you join and it does so right away without having to click reload several times a day...
I'm up for a talk about that and everything else... but let's do that on freenode