There have not been any announcements for a while for maquette. This does not mean that the project is abandoned or anything, there has just not been anything big to report.
But now that Typescript2 is released, we finally had something to improve. That is what the 2.4 release is about. If you are not using Typescript, version 2.4 does not contain anything new. If you are still using Typescript1, you should hold on upgrading to maquette 2.4 until you have upgraded to Typescript2.
Typescript 2 allowed us to use the readonly flag to tell which properties should not be modified. We also made maquette completely compatible with the --strictNullChecks option.