we are playing on a wrath of the lich king client (or whatever it's called), meaning there's no real balance between classes until level 80 whatsoever and it's not meant to be played on level 60. in my honest opinion, even those 2 months of wait for northrend release are too much, considering what i previously said. what i would like is that you expand the experience ranges to match the original TBC ones (around 500k exp for level 61 for example) so we get to explore the whole outland before reaching level 70. another thing is regarding seasons. i know we'll start on season 5 when we hit 80 and i would suggest making that season last for AT LEAST 6 months before moving to furious and another 6 months before progressing to relentless and so on. someone today said that each season is going to last for about 2 months or so, making the whole purpose of a progressive realm a joke.
anyway, these are the things i would definitely like the most. (to summarize: original exp from tbc for outland until 70 and long seasons on level 80 that last for at least 6 months)

