The lead developer of Heroes of Allacrost kindly let me know that a new version is due in the next two weeks.
The "other" Colonization-inspired effort, now called Colonies, saw version 0.0.3 out yesterday. I'm not sure how indicative of the gameplay state that version number is e.g. I wouldn't say that OpenCity 0.0.4 reflected the state of development, I would say it was more like 20-30% complete but what would I know! Anyway I don't have time to check it out properly but I eventually found the screenshots (not in the most obvious place).
Any really dedicated Free Gamer readers may note I said that they claimed to be an open source sequel to the 1994 original, but they are explicit that this is not the case (don't know whether I was being sensationalistic or ignorant or they have changed tact - was too long ago). However they claim it's open source but I could find no source code locations
What's this? 3D Wesnoth? As an RTS? Screenshot posted by the lead Wesnoth developer... maybe he's working on something eh? We'd be so lucky. :-)
There's now a roadmap for FreeOrion 0.4. I'm looking forward to the next few versions of this open source game, which is inspired by the Masters of Orion series. MOO II is one of those games that sapped up [too] many hours of my younger years. FreeOrion is very thoroughly designed and the graphics are very, very slick. When it's done, it'll be one of those FLOSS games that will be, um, simply awesome. The research UI is especially nice. Still, a few years to go before version 1.0 though.
I would post more but I gotta save at least a few things for another day. ;-)