Some analysts think that a “Stand Alone” Portal Server is dead. This follows from the fact that many portal features have been commoditized and made part of infrastructure/application servers. The fact that portal servers are expected to do much more than they initially did means that they have to interact more closely with services provided by application server. This gave app server vendors an opportunity to differentiate by providing portal features. Hence more and more companies are going in for infrastructure vendors like IBM, Microsoft and Oracle. Smaller vendors will either be gobbled up or will need to provide some niche capabilities if they want to survive in this market.
IMO, in the future, more and more clients will buy or use portal features provided by the application server vendor. Laundry requirements like search, content aggregation and integration, basic content management, personalization etc will be provided by these. There will be niche offerings such as eLearning, collaboration etc for which these organizations will buy products that will need to integrate with the application (or portal) server.