The program isn't very widespread, existing only on 14 US realms and 13 EU realms at the moment. There are lots of details of the program that are important to those looking to get involved in this.
Overall, this should be a nice way for Blizzard to not only encourage new players to find a virtual home, but for the veterans of us to extend a helping hand in a very warm, friendly, and Blizzard-backed way. It'll be interesting to see what effect this has in the long term!
Check out the full blue post, including a list of EU and US realms, and an FAQ, after the break.