Reasons to roll a DK
Anti caster in plate
Seems to be very active with lots of abilities, utility, and dmg.
Has group buffs
Not a tunnel vision class
Something new to do
Reason not to roll a DK
You start with crappy gear when your main would have full s4 and not get a gear upgrade until s5 started.
The class seems like it is going to be a lot of fun, that reason there is the only one I can think of as to not roll a DK as a new maun
You know what's going to be funny? The death knight class is going to turn out exactly like the hunter class. There will be a lot of them, but the class won't be retard friendly.