We finally have some concrete info on what exactly it will take to unlock the elite specializations. Well, sort of concrete. Let's call it slow-curing concrete. The gist of it is that we'll need 60 hero points to start using an elite spec. And a total of around 400 to unlock the entire thing. Jungle hero challenges will be worth 10 hero points each. Here's the quote from Colin Johanson:
"It works just like any other training line - except all the skills, traits, skins, abilities, etc. are all inside one full training line that costs 400 points to get everything in the entire line. It costs 60 points to unlock and be able to play as the elite specialization itself.
Currently anyone who has done all the hero points in the world has about half of the entire elite spec line unlocked on day one. Hero challenges in the jungle are worth 10 points each, so you'll only need to do about 20 hero challenges in the jungle [or via the new WvW system] to have everything related to your elite spec trained.
There are enough hero challenges in the jungle to train your entire elite spec and not do the challenges in core world if you wish - they simply speed you up if you've already got them."