*Edit* Seeing as this old post is still getting a lot of views – I wanted to redirect people to more recent information. Check out THIS and THIS for more updated patch 4.1 info and the patch 4.2 trailers (which include dailies) respectively.
A recent post of mine mentioned that daily quests would be coming, though I wasn’t entirely sure when. I went back and checked the information (credit to Wow Insider’s blog for confirming) and there will be a new daily quest hub added to Hyjal in patch 4.1. The term ‘hub’ suggests it will contain several repeatable quests, similar to deepholm or Tol Barad, and unlike the pair of solitary quests available in Uldum for Ramkahen reputation. Those of you dying to grind Hyjal rep for the great loot they offer, but don’t want to put on a green tabard and hit up dungeons should finally be satisfied.
Other content this patch will add is the Firelands raid, where we will kill Ragnaros for good, and a 5 man underwater dungeon in Vashj’ir. I’d imagine Firelands will be tier 12 raiding gear. Also, the Enhanced dungeon maps is expected to make it live in 4.1. Dungeon maps should be more detailed, including boss lore, abilities, and loot.