All the takeovers appear to be because of advertising the move to other IRC servers, ie the new freenode owner doesn't appear to be actively hostile, just normal drama?
If this is so, then we don't necessarily need to do anything. Don't make any official move, and if the community naturally gathers in one over the other, that's how it goes. We can add the other irc links in the circulating forum thingy that currently just has freenode.