Since v0.90, native support for showing "!" icons on the map was added, however it is still in testing.
Will only show your own faction if you choose to filter Opposing Forces.
An example of the main menu.
If you have TomTom installed, just click any quest to have TomTom map the way to the quest giver.
You can see at a glance what quests are currently in progress, and can see if they are complete or not by looking at the grey/yellow "?" icons.
If you filter completed quests, it will only show ones you still need to complete in the zone. Daily quests will never be marked as completed, so it makes it simple to see what daily quests are in each zone.
Can show both Alliance and Horde quests, or you can filter out Opposing Forces.