I used to think this too... but now I feel that lets really just blow through the low levels, the cost to gear up and getting pm stuff is just too high for playing low levels to be worth it, especially with a small user base... I mean if the game were presently 100% up to speed to where we were at sunset and you made us all brand new L150's at a snap of a finger we would have 2 years of content to play through between faction, gearing up, maxing out skill points, learning recipes, guilding up, etc, etc... and in those 2 years is plenty of time to make new content...
I would almost say just keep the 2x xp and cap it at around 110 instead of 75... that would give us approx L6 of everything before we switch over to normal xp.