FamilySearch has a 1940 Census Map showing the progress of the indexing project on a state-by-state basis. Colorado, for example, is 100% complete. The indexing for the country as a whole is about 16% done in 3 weeks or so, suggesting it might be finished by the fall if the current pace continues. I think that’s quite remarkable.
The Census Map also provides state-specific links to the FamilySearch Wiki that Pam Ingermanson showed us in one of her talks. Clicking on a state takes you to a page with a section labeled “FamilySearch Wiki Articles.” The articles describe the state’s vital records, probate records, land and property records, etc. If you’re researching a particular state, drilling down from the map is an easy way to locate articles describing its records.
You can still download the indexing software at the Project Page if you’d like to help.