All the consolidating revisions have been submitted. The sparse compilation project remains under very active development, but with a new home in the SparseTensor dialect, going forward we expect a lot less extensive renaming and refactoring (famous last words?). So, if you were interested in this project, but had not gotten around looking at the sources yet, this would be a good time to get more familiar with the sparse code base.
Next plans focus on front-end work (e.g. Python support for the annotations) and back-end work (e.g. improve sparse codegen quality, new features, support sparse output). Also, we encourage other projects that target sparse compilation in one way or another to start using the newly added sparse tensor type, so that ultimately we all “speak the same sparse language” and swapping in different front-ends and back-ends for experimentation and comparison becomes much easier. And if you feel features are missing in the sparse tensor type encoding, we accept PRs!