Language assistants and students in France will no longer be required to obtain a carte de séjour from the préfecture, as they have had to do in the past.
After the medical visit, you will receive a vignette to be placed in your passport. This will serve as a replacement for the carte de séjour, and you will still be eligible for CAF with this vignette.
The vignette *may* be valid for an entire year instead of just the duration of the assistant contract. Some details are still unknown and a little vague, but this change is to simplify the process for everyone involved. I'll post more information when it's available.