Isn't this already implemented? I returned last fall after taking a few months off and found I could see contribs from any IPv4 and IPv6 range right in the standard interface. It's awesome!

Special:RangeContributions. "Users can essentially think of it as a standalone tool for power users, as they do now with XTools." - yes. Right now all registered editors can use the same tools admins do when calculating ranges and looking at contribs. Most of them don't because they don't want to take the time to understand what they're presented with or they view it as an "admin" job. Don't think this spiffy new tool (thank you, thank you, thank you @MusikAnimal ) will result in a major change in that behavior.

@TheDJ Note the original request (and the request I made last year) referred to article space.

Yes, have multiple watchlists containing lists that I can control.

I looked at the proof of concept and I have to say, the UI is not what I was expecting. Copying this from the March-2015 English Wikipedia help desk thread:

Is this task being worked on? Or is it dead again?