Unlimited number of quests?

[amikot]

That would be very cool if we could pick any quest and do it later - by occasion.
Sometimes someone asks you to do low level dungeon that you didn't do, but you already abandoned quests for that dungeon because needed slots for new quests. In similar situations there is no time to do research where to pick quest that was abandoned. And finally even if you are going to the dungeon - you're not doing the quest, and not getting achievement.

[JARVIK]

Hi, this server is Blizzlike, and will follow Blizzard's quest system as it was in WotLK, which is limited to 25 quests.
You can download several addons that can help with finding quests that you haven't previously completed, such as EveryQuest or Carbonite.