I did enjoy the ending, but I am not sure what just happen. It almost feels both the end and also a new start. Probably misunderstood what was happening. Though it seems like they died whether it was before the plane crash or at the plane crash. Desmond was able to help bring each other together when it was time to end. Christian made sure to guide them there. Jacob and the Smoke Monster were something they created, which acted as two sides of everyones personality. The ultimate goal was to be Jacob. Jacob in the last episode final had the chance to join his brother. That was my jist of it.
i don't think so please read my reply before that one you will get better picture of what happen in the finale