I think that we can't expect continuous progress either, though. Often in computer science it's more discrete, and unexpected. Computer chess was basically stagnant until one team, even the evolution of species often behaves in a punctuated way rather than as a sum of many small adaptations. I'm much more interested (worried) of what the world will be like in 30 years, rather than in the next 5.
Its hard to say. Historically new discoveries in AI often generated great excitement and high expectations, followed by some progress, then stalling, disillusionment and AI winter. Maybe this time it will be different. Either way what was achieved so far is already a huge deal.