The reason I was amazed is not the fact that the FSF is now publishing such a newsletter, but rather the fact that I did not hear about that yet. Basically, the Supporter is about informating the Free Software enthusiasts about recent happenings and the work of the FSF, the GNU project and the global Free Software community.
It seems as if I am not the only person that is excited about the supporter, as Joshua Gay, who apparently is writing the Supporter, also seems to like it, as he writes in a blog post:
I hope that you enjoy the Supporter. I am looking forward to reflecting each month upon the work of the FSF, the GNU project, and the global free software community. I only hope that the number of highlights I add each month will continue to grow as quickly as the community is growing. In either case, we hope to keep it short and we hope to keep you informed.
You can sign up to receive the Supporter via email on a monthly basis at http://lists.gnu.org/mailman/listinfo/info-fsf and you can read the first issue online at http://lists.gnu.org/archive/html/info-fsf/2008-03/msg00000.html.
Also, if the Supporter looks like an interesting read to you, you may as well enjoy the monthly newsletter the FSF Europe publishes. The FSFE Newsletter can either be read online or you can sign up for the FSF Europe press-release mailing list.
Personally I believe both newsletters are worth reading and give you a great overview of what has happened in the past month, what is going to happen and the work done by the FSF and FSF Europe.