As for the rest of the rogue toolkit, I'm decidedly ambivalent about the whole thing. The rotation for an Assassination rogue isn't what I'd call particularly complex, it's simply a matter of watching timers to make sure you're performing the right moves at the right moment. Mutilate, Rupture, Envenom -- they're all abilities I use regularly. There's nothing really remarkable about them. I like that Envenom refreshes Slice and Dice, but that's not really liking an ability so much as liking a side effect of using that ability.
Which is really kind of weird, when you think about it.