As to whether there will be a decline in the hub model, or whether it will stay the same while point to point grows - I think largely depends on the growth of air traffic. If air traffic grows substantially, I think the hubs will certainly decline, at least on one side of a transatlantic journey.
For example, BA currently serves 21 Gateways in North America, a few of which are not major hubs, like TPA, BWI, SAN. This means that a lot of people can get to any BA destination in Europe with only one connection. As more and more cities get service to Europe, more and more people will be able to reduce connections on a transatlantic journey. Furthermore, as these secondary cities in the US get service to London (in this example) the larger US cities will see increased service to secondary European cities: like Manchester.
Because the top 20 or so cities in the US are already hubs, and most of the major cities in Europe are hubs, to some extent I think the hub and spoke model will always be important. However, the web connecting individual cities is gradually increasing due to smaller aircraft performing economically.
RogueTrader's Timeline for transAtlantic movement away from hub and spoke:
1935 to 1975: all N. American traffic changes planes in New York, then changes planes again in London, Paris, Amsterdam, or Frankfurt if going on further
1975 to 2000: the rise of the hubs in N. America. During this period, JFK declines in importance and loses traffic (which it has) as other hub cities gain their own nonstop service to Europe
2000 to ???: The rise of non-hub N. American cities seeing service to Europe, some secondary European cities see service to N. America
??? to ???: secondary cities on both sides of the Atlantic see service to other secondary cities on the other side of the Atlantic
Yes, the hub and spoke will always be required for service from Duluth to Lille, but more and more medium to larger size cities will see a decrease in the central importance of hubs.
Southwest, Ryanair and the other non-hub carriers are the way of the future. People do not enjoy going through hubs.