Pretty sure we'll all be able to experience the new story without making new characters. That's what it sounds like when the devs talk about it. I'm sure they wouldn't exclude the loyal fans who stuck with them so long. ;3

I would definitely get at least one 50 before 2.0 to experience the one-time content in the game right now. Don't wanna miss out on that epic story. Unsure about items that may be unavailable later.