So heroic mode

I don't know if there's any info about it, but what should we expect with the heroic version of the Argent Coliseum?
Will it be like actual hardmodes where the bosses get new abilities and stuff, or will it just be the same bosses with more HP/damage?

Heightened damage and health is definitely going to be involved. I imagine at least a few of the bosses will have nothing more than that. I don't really expect more than 1 or 2 bosses to have any extra abilities.

As far as I recall, Anub'Arak kept spawning adds during the final phase of the fight, which he didn't do in normal mode... so that's one thing. He may have also kept spawning them during his burrow phase -- but I don't really know how that fight works. Also, the frost clouds were limited in heroic mode.

This info may be outdated.