Mageia was announced previously on LWN. As the other person said, it is like Mandriva, but then the older days. Very active community, seems the amount of packagers is growing pretty quickly.
They're pretty friendly towards new people wanting to help packaging. At any time, it seems like about 5 people are being trained (good be more, but only some packagers volunteer as mentors). Every new packager is guided by a mentor; someone who you can ask questions to + someone who offers suggestions. Then after a while (once considered good enough by your mentor) you get full packaging rights. I started helping out just because you get a mentor + availability of easy to follow packaging guides on https://wiki.mageia.org.
And why Mageia? No real reason other than that it is a friendly place and you can make up your own way to pronounce Mageia :P