In the UK, mega-malls are doing great whereas small ones are faltering.
I think it's because shopping is now an experience rather than a necessity: people go to mega-malls to eat out, see a movie, and have a look at shops where they may or may not actually buy anything. Large chains can then use their megamall-based shops as showrooms/customer-care contact point/"prestige" destinations. You only need one or two per city, of course, so they close smaller shops elsewhere which acted as anchors in smaller malls or retail parks.
eCommerce is increasingly centralising retail in the way IT centralised distribution 20 years ago. This is also why a lot of UK small towns are suffering (they are, in the end, primitive shopping malls).
I don't know exactly what marks or causes the split, but it's very much there to my eyes.