The RDF is produced 3 or 4 times per month, about weekly. Occasionally one is missing if it has errors, or there was downtime with servers, etc. There are server upgrades going on for several weeks now, so there have been interruptions. Expect to see the next one in the next week if there are no further problems.
The RDF is used for many things. It is used to update the ODP search. Due to upgrades, the search is unlikely to be having new RDF data for at least several weeks.
The RDF is used by downstream users such as the Google Directory. They have their own update schedule, and may be back tomorrow or may not do anything for many weeks or months. We have no way of knowing.