Personally, I think that given enough of them and time, some intelligent species would find a way to explore the galaxy even at sub-light speeds. I also think that they will do so via some form of what we'd call AI. But it may be that such things as I believe are somehow just not possible. Or maybe there are no other technological species anywhere. Or maybe they all did transcend to another form of existance such that we at our level of perception simply cannot detect them by any conceivable means. We really just don't know.

I'm in the camp that all our sci-fi assumptions need be questioned down to their roots. Maybe that process will open up new fertile areas of investigation. Meanwhile, we're stuck with planetary probes, missions like Kepler, etc. to get at least some baseline data. It's better than pontification.