Quite a while? Quite a while! Yup, Bioware is on the money with that accurate assumption. It's no wonder you believe them.
People will be 55 in 24 hours or less after head start launches. That really is "quite" a while, isn't it?
People were 70, 80, 85 and 90 in less than 24 hours in all of WoW's expansions. And they cost full price.
So, what is your point really? That some people are content locusts and rush just to be the first and the complain that they are bored? It's like finishing your Christmas Dinner in 2 minutes and then complaining you are bored because everyone else is still slowly enjoying theirs. You know who do that? The little annoying cousins.. the ones everyone wish would just shut up and let everyone else enjoy their Christmas dinner.
If the levelling arch is equal to 45-50 was, then most people will probably spend about a week or two of their playtime going through the quests and areas to get their 5 levels of experience. Even now, with my characters that I am rushing to 50 with boosts, it takes at least 3 evenings of 3-5 hour play sessions to get them from 45-50. And that is with skipping all dialogues except class stories.
But naw.. unbased hyperbole about no-lifers being able to do it in the first 24 hours of the new planet is what we need to measure content on. Not on actual facts and experience from what we have in game now and how the other 99% of the players play this game.