Musings on web magazines and national libraries/archives

I know I have already mentioned this in a f-locked post, but I thought it deserved some wider consideration.

This blog post describes how the online knitting magazine Knitty is now being archived by Libraries and Archives Canada

Which means, in theory, that it will never go away. Unlike the recent disappearance of an online UK knitting magazine.

This leads me to wonder whether archiving exclusively online publications is something that all national libraries should be looking into? How would it work? Interesting things to ponder at a time when I am becoming more interested in e-resources (much to my surprise)