There's some bad news. Save express which is an online store in Germany reported in their newsletter that a Danish producer of incontinence products decided to completely stop the production of plastic backed diapers in 2012. Abena's products I know are made in Denmark, so I contacted Abena about this for further information.
Their response was that indeed the production of plastic backed diapers will completely stop somewhere in 2012. They don't know if that will be in early, mid or late 2012. This means that once the production stops, the popular abri-form diapers with plastic will most likely not be produced ever again and will become rare and more expensive.
I know the m4/l4 diapers are the favorite diapers of many including me, so that's why I'm informing you about this. If it wasn't that I live with my parents and if I could stash them somewhere, I would order about 50 packs for the next five years, or maybe even more. I think this is a waste of what is at this moment still a very good diaper and I'm afraid more producers will follow.