I suppose that the Star Wars Galaxy would hit a technological plateau where there wouldn't be that much of a change for thousands of years.
Technology has been rapidly advancing for us since the Industrial Revolution but before that it stayed pretty much the same for a very long time.
If we reached a point where all things that were practicle for us to use were discovered (or discovered to be impossible to build) we might settle back until our circumstances changed when we found new problems to solve.
You'd assume that weaponry would become more powerful in 3500 years, everything looks just the same as we're used to seeing, blasters etc... And you'd assume a city like Coruscant would be in need of a serious face lift, most city's change over a few hundred years, Coruscant again lkooks pretty much the same, don't they have different periods of architecture in the Star Wars universe !? :)