Reading the excerpt today i saw that the adamantine makes 4 attacks with a standard action, this is much more attacks (and damage) than the red dragon (other soldier dragon), are the monsters becoming more strong?
Its defenses are a little lower, and it apparently has fewer hp. So wotc might be trying to make fights with solos go quicker, but they deal more damage in that shorter span of time.
Maybe they finally understood, that a solo monster needs at least 5 attacks a round to compete with the players. Preferably more. The Adamantine is the first dragon thats a really tough customer. They also lowered his HP a bit I think to reduce the grind.
If they simply had a single attack which did a lot of damage, you get one of two outcomes - either it hit and dealt a lot of damage, or it missed and did nothing (neither of which is fun).
Conversely, if you made a lot of attacks, some will miss, some will likely hit, so your actual damage gets averaged out, thus it is more balanced in a way (in that you are assured of at least some damage each round).
