As a newly hit lvl 70 Shadow priest with mainly blues for gear, I consistently crit in the 2100 range, and that is with roughly 350 in + dmg gear pending which gear I am running with as I still do a lot of healing runs as well and sometimes mix and match sets to maximize what I need for the run.
With the talents provided by the Shadow tree, you can consistently see that type of damage from your mind blast every 2 or 3 casts. Add in the SW: D for abojut 1800 right now and you will see crits flying all around. As I run with a pally all the time, I am also not afraid of throwing out a SW:D early as I know my VT/VE combo will help heal me and the pally will keep me up as I am feeding him a constant supply of mana.
I cannot wait to start getting into the better gear to where I will be closer to the +750 range so I can really start seeing the damage pouring out.
Since BC came out I have stopped leveling my Rogue alt as I realized that the damage we as shadow priests are able to put will put as at or near the top of the damage meter and our versatility is greater than that of a rogue for all groups as we added dps, off heal (main heal if needed), and buff all the casters out there with misery and all shadow damage with shadow weaving.