Nah. Clerics will outlast paladins at the very least, because if those are the last two divine casting classes left, clerics are so much more flexible. You can reasonably well approximate the paladin as a lawful good fighter/cleric, but can't build a cleric out of the other classes. I'm pretty sure the original four base classes (and their successors) will be the last four: the most flexible archetypes, of which the other classes (except monk, which is totally bizarre) are all essentially variants and combinations.
And looking at the polling, you're wrong about the ranger too. It'll be in the final five.