Resto4Life has updated their very helpful Mana Regen Calculator -- if you want to figure out just how much mana you're picking up while buffed and dressed in a raiding or group situation, it'll tell you, including talents, items, and even abilities used on you (Innervate and Mana Tide totem). Pretty slick.
The new update allows for Mages to have a set of abilities of their own, including Mage Armor, and Evocation, which means that Druids, Priests and the followers of the Arcane all have their chance to see how much Mana they're getting back per tick. Shame that Shaman aren't on the list yet (maybe all of the mp5 on Shaman abilities and gear would make it too hard to do?), but if you're one of the listed classes, it's a terrific resource for seeing what your Mana regen abilities are like and how you can best make use of them. Very cool.