Doesn't look like there's climbing anyway, so there.
I do hope they're open : it does make levitation possible, and more importantly, aerial dragon attack, no ? :unsure:
Well the skill Climbing, might not be in, but the ability might still be in, either way, Oblivion didn't have climbing, but people still found a way to get over the wall, it will happen in Skyrim, I see a wall as a challenge

Anyways, as long as actually getting over a city wall, loads the city instead of just voiding out, it'll be okay (for me).