[Network theme, Domain Mapping plugin] How to replace the Network theme, and the Domain Mapping pl

First of all, what has happened to the Domain Mapping plugin?

And secondly, I am still using the Network theme on 3 of my installations, which means they are running on older versions of PHP. The Network theme won't work on newer versions. I really need to update the PHPs, so is there a way that I can emulate what the Network theme does – showing the latest post from each sub-blog?