While browsing the The Server Side’s list of Most Requested Content for 2007 I ended up reading about Google’s algorithm MapReduce, Grid Computing and Giga Spaces. For the (admittedly rare) cases where the applications really have to scale to huge loads (read Google, eBay etc) JEE app servers do not seem to cut it. This is probably because there is no support for Grid Computing /massive parallellization.
Being a Spring advocate I am not at all surprised to read that there are some people that feels the time is ripe to replace JEE application servers with something new. Kimchy believes the Giga Spaces /Open Spaces is a precursor to such a next generation application server, much like Hibernate was to JPA.
I am not sure whether something like Open Spaces will replace JEE App Severs anytime soon (I need to read up on these, for me, new enterprise patterns in general and the Open Spaces project in particular) but I do agree in his thoughts there is a need to simplify and coordinate many of the services needed to develop a truly scalable application in a new app server like container. A container where something resembling JEE packaging can be used to deploy and manage applications.