We heard the debate about MARC should die or live long time ago. Here is a blog post "Who needs MARC?" talked this old topic again, with some fresh points of views though: "MARC is NOT a data storage format. In my opinion MARC is not even an exchange format, but merely a presentation format."
"It really does not matter how you store bibliographic metadata in your database, as long as you can present and exchange the data in any format requested, be it MARC or Dublin Core or anything else."
However, the post had to admit that there is no widely accepted alternative so far and it takes time to develop a better international standard.