The way I read it was that Justice Points at 85 could be used to buy level 85 gear, be it blue or epic, to help prepare for raiding.
Actual raid quality items (like orbs) would require the higher-level tokens.
Each time a new tier is released, all T2 points are converted to T1 points and all items which were purchased with T2 points are now purchased with T1 points. Then Blizzard adds a new T2 vendor and makes the new raid tier the only place to get T2 points.
My question is whether or not bosses in lvl 80 heroic dungeons will still give points, and how many.
Good question, my guess is that they won't, and that if they do, it will be a marginal amount.
EDIT - Or maybe they will but only if you're the relevant level.