Future expansions.

there won't be dragons as units

I'm so tired of explaining this on different forums. I've already said it in this thread. Oh well. One last time.

When the developers said that there wouldn't be dragons, it meant that there wouldn't be dragons only in the original Heroes 6 (without expansions). Producer Erwan Le Breton meant that dragons would be bosses. But he was misunderstood... And this led to the incorrect assumption that there wouldn't be dragons even in the expansions as units.

Here's a video: http://www.youtube.com/watch?v=n01iggq97gI

In it, Marzini, in clear English with a strong French accent, says (3:45) that they didn't include dragons as champions in Heroes 6 because many complained that in Heroes 5, half of the factions had a dragon as a champion. I quote:

But this does not mean that in the future we will not have a faction with a dragon as a champion. I think you will agree that some factions cannot exist without dragons in their lineup of creatures.

Hopefully, it's clear which faction he meant.

well, assassins are no longer archers (see the art)

I don't see the assassin's art in the compendium or anywhere else.

Added after 8 minutes

Why is everyone so sure that it's a manticore? The creature seems to have horns! Although the appearance certainly refers to the manticore from the third game.

Creatures can change their appearance significantly when transitioning from one part to another. For example, succubi were originally wingless; phoenixes were fiery, not blue; and centaurs were initially half-horses, then half-nightmares, then half-zebras.

It's clear that it's a manticore because of its tail.