With the item squish all the numbers are dropping dramatically, but we will still be at lvl 100. When a new player joins the game, lvl 100 is a long way off, and can seem very intimidating. With every expansion the xp needed to get from one level to the next has gotten smaller and smaller for the old levels and gotten insanely big for the last few levels of the new expansion.
So this is my suggestion: why not squish levels and xp as well? it will make this much less intimidating to new players, and will bring the level curve back to something reasonable.
it could look something like this:
Vanilla: 1-40
Outlands:38-45
Northrend: 43-50
cata: 48-55
pandaria: 53-60
WoD: 58-70