Since they're still going for the multiple entry approach, what I think will happen is each game will be its own thing, they'll be adding enough story that once part one is finished, it'll feel like you've finished a full game but will be eagerly awaiting the sequel that will finish off the over-arching storyline, especially since there are so many points they could end it on that would be cliffhanger territory for anyone that hasn't played the original game, lol.

If this ends up being the case I imagine part two, or whatever they're calling the next episode/whatever, will start you off back at Lv. 1... although maybe you'll unlock some fancy items if you have a completed save file from the first one? I honestly couldn't say what I'd prefer, but considering the amount of content they're promising (Surely there has to be a lot, since we're getting this first part on two bluray discs, old school as fuck!) I don't really see it being a problem.

It's not like what you described in the first sentence. Yes it's a multi part game, but the main story is already set in stone, and part one is 2 Blu-ray disc long.

2 25GB or 2 50GB discs

It is what I wonder, will each episode be a game in itself(start from lvl 1) or you need the save of previous episode so you continue from the same state you finished the previous one.