Zure

These numbers seem to indicate that for any reasonable number of physical dps, imp expose armor is now very much better than sunder + rupture. 475 armor pen is about 3.5-5.0% more damage per physical dps (depending on equipped armor pen) and rupture seems to account for about 6% of the average rogue's damage output.

If expertise geared tanks can hold agro with weaker devastates (possibly with SS, Revenge, Shield Bash, Dev, repeat with 2x dev instead of shield bash), that's a noticeable jump in raid dps.