It's hard to say any more without completely giving away the plot, but the early ramblings of new kings being old kings being new kings actually does make sense. The lowly screen resolution has been boosted from a miserable 640x480 to a much more respectable 800x600, with unofficially supported options going right up to 2048x1536, for those of you who bought your computer from Industrial Light and Magic . The higher res. And it's not just eye candy, either. Bards and Druids, useless in the original, have been made much more effective and given some new spells.
Paladins also gain their spells much earlier than before.
You'll also find the AI has improved somewhat. It's now much harder to get enemies to fall into a trap by 'picking them off' and enticing them to follow a character into a trap set by your party. You'll still get them to follow, but there's a fair old chance they're going to bring their friends with them. Lobbing a fireball at a goblin no longer means it's friend just stands there picking his nose, he'll either attack or run to get his friends. Much better than before.