Any opinion about whether it's better to put them in the same or separate actual repos? The general rule in git is that a repo should contain a single project. There are some projects that violate this rule - e.g. cabal stores both Cabal and cabal-install in the same repository - but with such a setup it is harder to manage commits in case some of them need to be reverted. I'd say that if we split lambdabot in such a way then core should be one repository and contrib should be another one (separate). Contrib repository should contain only one package (instead of bunch of smaller ones).
couldn't get a response from whoever was the current maintainer Speaking of which, I think you could become the current maintainer since both Cale and Don agreed that the project should be maintained and you seem to have done a lot to improve it. Not saying that you should do all the development, but you could manage releases and uploads to Hackage.
I don't have too much time to spend on this, but I will try to regularly spend 2-3 hours a week on lambdabot. Janek