Amusing to me to see the return to concepts that the dynamic web started with in the form of CGI, mod_perl, Cold Fusion, PHP, ASP.NET and all that. It’s the same, but different. Next we’ll be on to multi-tiered caching.
What’s the difference conceptually between islands and e.g. Hole-punching in Varnish? The result in each case seems to be a site that is mostly static with some dynamic portions.