In addition, Drysc goes on to add that they are interested in "refining (?)" a couple of the old-world instances, namely Gnomeregan and Uldaman, because apparently those dungeons tend to get more people more often during the leveling process. "Refining" those dungeons could mean anything from changing some of the trash mobs to really reorganizing parts of the instance, and the effect could be for better or for worse -- several of my friends tremble with hatred at the mention of those two instances, and would much rather Blizzard removed Gnomeregan and Uldaman altogether than encourage us to go back to an "refined" version anytime soon.
For my part, any refining of old-world content is a good thing. It would be good to speed through content that most of us have already seen before, and it would be refreshing to revisit some old dungeons with new twists for those of us who haven't already done them to death. Some players, however, are crying bloody murder -- apparently ones who enjoy repeatedly slogging through hours and hours of the same old content and think that everyone else should have to also.