I just visited my FLGS, and while the owner didn't have the Dark Sun books, he had been to Gen Con and brought back the D&D comic being given away there. So far it doesn't look like anything special, although the black dragon in the comic has a fun line that I'd like to use in a game: "Pray for death. Pray to me. That would amuse me." There's also a Dark Sun comic; strangely, the first comic is about an entire party of adventurers, while the Dark Sun one seems to focus on a runaway gladiator and the bounty hunter tracking him down. The Q&A at the end of the book also promises that different powers and feats will be represented visually.
Speaking of the black dragon I mentioned earlier, it's stats are presented at the end of the book (apparently statblocks for any new monsters and villains introduced in the comics will be included). What's notable, though, is that this black dragon's stats are radically different than the beast in the Monster Manual:
* First off, the young black dragon is presented with the MM3 statblock.
* Damage has been upped all around.
* Acidid Blood is a new trait that activates when the dragon is bloodied. Each creature adjacent to the dragon takes acid damage when the dragon is damaged.
* Instintive Devouring lets the young black dragon charge, bite, or end a dominating or stunning effect on an initiative of 10 plus its initiative check.
* Action Recovery puts a stop to dazing, stunning, or dominating effects at the end of the dragon's turn.
* The Breath Weapon no longer inflicts a -4 penalty to AC.
* Cloud of Darkness is gone. In its place is Shroud of Gloom, a power that confers vulnerability to acid damage and a -2 penalty to attack rolls until the end of the encounter. These effects can also be ended with a DC 10 Heal check.
* Tail Slash has been replaced with Tail Sweep, which is not the same power as the one used by the Monster Manual's green dragon. Tail Sweep is triggered when a creature misses the young black dragon with a melee attack (the green dragon's version of the power was triggered if an adjacent enemy didn't move on its turn). Not only does it knock the target prone, but it also deals damage to each of the target's adjacent allies.
This is a much better version of the young black dragon, and I hope all the chromatics get this treatment (it had also better be added to the Monster Builder).