Personally I think the way Mandriva maintains both updates and backports for each release is a waste of resources.
I do agree that Mageia should be a semi-rolling distro. By "semi rolling distro" I mean the following: Release a distro every 8-12 months (the exact cyle is not the point I'm debating here, it could be 6 months too, it doesn't mater for the concept I'm trying to explain). Provide updates/security patches for all the basic stuff that has a lot of dependencies (kernel, core libs, kde, gnome, xorg, etc.). Provide newer release rather than backported security patches for all other apps. In other words, backports (rather than backported security fixes) should be the rule for everything apart from the core system stuff that has loads of dependencies. This would reduce the space requirements on the mirrors and it would mean that Mageia is a "rolling distro" for most apps, making it more attractive compared to ubuntu/Fedora/opensuse and at the same time reduce the workload for packagers.