I'm not sure which beta builds you tested or for how long you tested but leveling slows way down towards the end of Chapter1 and start of Chapter 2. Will there be people at 50 by the official launch? Probably, but they will be hardcore people that have barely slept,eaten or showered in a week.
If the average gamer(read casual) plays 4 hours a day,which may even be high, and the class story alone has 200 hours of game time they are looking at quite some time before they hit 50 if they maintain their 4 hours day.
maybe you are right i got one to 22nd level with no slow down as i found that there was no real increase of XP necessary quests to get to another level and this was playing a little here and there.
you might be right but i didn't see it and if they are putting the 4 hours a day as the rule they are off since yes there are a lot of casual there are a lot of people who play more than this and it is easier to have it take longer for casuals than it is to have a steady drop off post launch <Rift was one of these as the week of launch and maybe for 2 weeks it was really busy then servers started being closed and slowly subs dropped>
not sure if the story lines after the first bit stay complete different or not this was another issue in Rift since you had to repeat all content.
not saying the game will fail but the cheering section didn't do anything for all the past hopefuls that barely got off the ground.