Hi there,
It's my first post, so I hope it's okay to post something that's a bit more general in here, but I think that since regen is such a concern for us now, it's relevant.
In-game, the game shows two values for mana regeneration under the spells category. The first is "Mana Regen" and the second is "Combat Regen".
What determines the value for "Combat Regen"? I understand that meditation adds half of your Spirit regen (what it says when you mouse over your spirit stat) but I don't know where the rest of that value comes from.
The formula at:
Mana regeneration - Wowpedia - Your wiki guide to the World of Warcraft
seems to accurately describe the MP5 that spirit will produce, outside of combat. But that formula doesnt account for the rest of the "Mana Regen" value, only the spirit component. For reference, here's some data from my characters
Priest, lvl 70, disc spec, has meditation
Intel 594
Spirit 258 (increases mana regen by 175)
Mana Regen 306
Combat Regen 218
Wowpedia regen formula: MP5 = 5 * (0.001 + sqrt(Intel) * Spirit * Base_Regen) * 0.60
Where Intel = 594, Spirit = 258, Base_Regen = 0.009327
Result: 175.9476882
Since we know that half the difference between Mana Regen and Combat Regen here comes from meditation, we can derive that the baseline regen is 130.
Druid, lvl 73, balance spec, no meditation
Intel 564
Spirit 406 (increases mana regen by 231)
Mana Regen 366
Combat Regen 135
Wowpedia regen formula: MP5 = 5 * (0.001 + sqrt(Intel) * Spirit * Base_Regen) * 0.60
Where Intel = 564, Spirit = 406, Base_Regen = 0.007993
Result: 231.2076973
Since the druid has no meditation, 135 is its baseline regen.
The minor difference between both characters would seem to indicate a baseline regen value that is tied to your character level, though this is insufficient data to draw a general conclusion.