Originally Posted by
Kanadei
Short answer no.
Long answer - Critical strike from procs doesn't currently count towards riposte, making it virtually useless for protection as the only thing it is doing is adding a little bit of dps. The bonus armor on the trinket is nice, but not extremely high and there are similar alternatives that drop from heroics without having to shell out the gold (or resources) for something like this.
Addendum: This all goes out the window if you upgrade the trinket in a timely fashion, but since most people here are likely planning to raid - odds are you will get something better long before upgrading the trinket becomes worth its while.