Apparently Blizzard has the plan to add 10 more levels to World of Warcraft with every expansion. That is fun for everyone who is stuck at the level cap, which isn't all that unlikely given the long development time for WoW expansions. But it is problematic for anyone starting a new character, be it an alt or a totally new player: the way from 1 to the level cap becomes longer and longer, and everything except the last 10 levels tends to be underpopulated. Blizzard's proposed solution is to speed up the time to level through the lower levels, since patch 2.3 it only takes half the time to level to 60 than before.
Minionman wrote me with a more radical proposal: He wants to eliminate levels 1 to 60 completely, and remodel all the old Azeroth zones into level 60+ zones. Every new character (and not only Deathknights) would start in the normal newbie zone, but at level 60, and the mobs etc. around him would also be level 60. He would then have a large multitude of possible options to level from 60 to 70, using a mix of Azeroth and Outlands zones.
I don't think that the idea is all that good. First of all starting his very first character at level 60 is confusing for a new player. Levels 1 to 60 do serve a purpose of training people how to play their class, by starting with only a few basic options and adding new options over time. Starting with lots of spells and talents is too complicated for a player on his very first MMORPG character.
The other problem is that I'm not even sure that it would solve the underpopulation problem. We would still have the same number of people below the level cap distributed over the same large number of zones. It would be easier to find somebody in your level range, but not necessarily easier to group up with people you meet while adventuring.