Brief background -- Long time D2 player, played almost entirely on hardcore, usually died around level 70 in hell due to getting overly cocky on runs I had already done dozens of times. I will play entirely on HC in D3, but do not have the time that I had back in the day to devote to gaming.
The thing I am the most excited about, so far, from the beta is how levelling new characters is going to work.
The fact that the artisan stays levelled means that when you level up a new char, you will not need to farm with your main in order to twink your alt. The artisan can craft level appropriate gear for you. This, effectively, means that each play through can easily be a "normal" progression without ever dedicating time to farming other than end-game content and during your first play through. This should make the game feel more natural, and be more conducive to people with real-life responsibilities enjoying the game.
Purely from the perspective of someone who WANTS to be able to poop-sock, but can't because of time restrictions, this design choice, among others, has me very excited.