Unified User Interface
Content Aggregation for Portals makes the point that many companies are looking to use portal technology as the single, unified user interface to all the applications and content of the enterprise.
The Portal-Content Connection reports on a meeting with companies producing content management software. The question discussed was, 'Will content management and portal technologies continue to be combined together?' Yes, appears to be the answer, they seem to be more and more interdependent.
Portals as Integration
Portals: Much More Than Mere UIs is a good article explaining why Portals will continue to grow in importance. Namely, they are a critical part of enterprise application integration. The PDF is here.