I think what the Rogue really needs is something to do with its off hand. Perhaps some form of dual-wielding; perhaps some form of Dexterity-based shield. Perhaps both; options are good. Or perhaps neither, and some other solution I haven't thought of yet. Whatever works. The point being, pure Rogue isn't a wise course of action at present.
I think maybe reducing some rogue AP costs to near nothingness could be a good solution. Having the ability to just demolish a single target would be a very good step in the right direction.
I'm not saying they don't kind of have said ability right now but they don't stand out enough compared to other builds.