I have been doing some research and thinking lately about AJAX and how it might change (enhance) the portal world. There are two schools of though,
1. that it will revolutionize the way we develop and use portals, and
2. that it will simply provide additional capability for some portal applications.
I will say that all this new capability is definitely leading us toward heavier pages, for better or worse, I do not really know. I know it is changing the way we handle performance testing. The heavy pages slow down initial response times, especially as the browser tries to make sense of everything and spends time rendering the page. Fortunately, most of the bigger script files can be cached at the client to relieve some long term stress on the portal or web server. AJAX will also change the request pattern that is put on the appserver somewhat. Fewer page requests on the portal with smaller requests, repeated more often, from AJAX enabled components.
This growth also starts to blur the line between a separation of concerns in the development model, and the responsibilities of different layers in the system. I am still trying to work through where the line should be drawn between a presentation layer using JSF and the model, perhaps using a lightweight framework such as Spring. Moving more functionality to the client side confuses me again, but it is probably not all that bad, and we can still leverage whatever model layer we determine is appropriate. Definitely this is something we should watch as things evolve. I guess this is true with all types of applications, but since my focus is portal I tend to have blinders on sometimes.
On the lighter side, take a look at some of the cool things you can do with this technology around portals. Here are two portals that allow for very flexible portlet positioning. I think you will enjoy them.
I have to admit that I only spent a minute or two on each site moving portlets around. There may be more capability there, then I am aware of.