From what I understand, you are right about expertise, at least for assassination. If you look at the EP of each stat, expertise has taken a nose-dive. As an example, expertise gems are 41EP, while agility gems are 104EP. There is more value in adding hit to poison cap, haste, mastery... over expertise. If a special happens to be dodged, you regain 80% of your energy wasted anyway.

Mostly sourced from EJ's rogue forums.

You will still want to be at least dodge capped, parry is less important so long as you stay away from the front of a boss, as anyone should. Both caps are good to aim for with the few fights that require you to be front facing (super rare).

AEP value of expertise doesn't accuratly show that it is still needed at cap before moving on to other stats, because isn't it just awful when your envenom is dodged right as your slice and dice falls off?

Indeed. I'd like to hear more about the issue with Expertise. From what I understand, it has been devalued for all specs since dodged finishers no longer cost full energy. Expertise has been devalued even more for Assassination after the latest buffs to its mastery.

I'll be raiding as Assassination, and the min/maxer in me wants to do the "right" thing and reforge for mastery and/or haste. However, just subjectively it feels wrong to simply ignore expertise. About a week ago Ghostcrawler posted an article about secondary stats, mentioning that for hit and expertise, "it's intended that they are very good up until their caps". Seems like they missed the mark for Assassination.

Expertise over the dodge cap is never a good idea. And it would take 2-3 dodged envenoms in a row to let SnD fall off.

Don't gem expertise over agility. Only reforge to expertise (or any stat) if it is better than the stat you are reforging from.

"dodged finishers no longer cost full energy"

What do they cost? Did they make Quick Recovery baseline or something?