Well I would like to see no lascannons on the defiler, since his BC should do the trick. There is little armour on the field so I can see this guy getting taken down quickly.
I agree with Titan about dropping the plasma pistols, because most likely you will get to shoot them like once, and then they are just a regular pistol in CC. Way too overpriced in my opinion.
I love obliterators.
A nurgle DP would fit a theme better, but Lash is pretty potent if you use it well and if your opponent expects you to have no psychics.
I like the raptors, but as Titan mentioned, they need to be in a bigger squad.