Probably a bit late to post this, but ah, well...
I've spent a lot of time paying attention to wonders and what they do, and most of the stuff in this topic is correct. There's also some left out info as well.
Norse - As mentioned before, this wonder powers up the food, wood, and water miracles. Food and wood yield more. Water becomes stronger in that it puts out fires much faster, depending on how many wonders you have and how large they are. What hasn't been said (unless I've missed it) is that the wonder-amplified water also increases the rate of trees sprouting from watering other trees. Now, don't take this the wrong way and think, "Oh, then I'll just build a bunch of artifact powered Norse wonders and have a ton of trees!" It doesn't work quite like that. An unpowered water miracle will normally, in my experience, yield one or two trees in ~two waterings. With a bunch of wonders, it makes it almost guaranteed to sprout, at most, one or two trees from ONE water miracle.
Celtic - Powers up the storm. I want to say it powers up something else, but I can't seem to think of what it is. This wonder doesn't really change rank one storm, but it makes rank two ignite powerful fires when lightning strikes something. Rank three makes the lightning and tornado more powerful, but no fires ignite (unless my game is buggy, even though it's patched). I THINK it MAAAAY empower the forest miracle, but it doesn't cause much of a change, if I recall correctly.
Indian - It DOES increase birthrate, in my experience. The villages I build these in usually have a huge burst of population. It also speeds up villagers and, depending on how many of these wonders you have, makes them move so fast that it's hard to pick them up, even when pausing the game and unpausing when you're hovering over them (main reason I never build these anymore, as I don't need help increasing my population growth). It also increases the POWER of the lightning miracle, not the duration. Rank one lightning will destroy buildings pretty slowly, but with some of these wonders, those buildings will be destroyed with just one lightning bolt.
Tibetan - This one increases the bird miracle and I THINK the shields and teleport miracles. The amount of birds increases with one of these wonders (and with a lot of these wonders, the birds will stream from your hand for waaaay over ten seconds, making it impossible to set stuff down safely on the ground, until the birds stop spawning). Increases shield strength, I'm pretty sure. And IF it empowers the teleport, it increases the duration that it will last.
Japanese - As said earlier, this one empowers the heal miracle and reduces that village's (I THINK it's just the one village that the wonder is in) desires.
Egyptian - Also increases the teleport and bird miracles, maybe the shield in the same way the Tibetan wonder does. Another wonder I feel like there's something missing, but I can't seem to recall what it is at the moment.
Aztec - Destructive miracles EXCEPT the lightning miracle or storm miracle. My aztec wonders NEVER empowered my lightning bolts/storms, whichever one it is (heck, it may have been both, I can't remember

)
Greek - Wolves and, again, if I recall correctly, makes your villagers hardier (tougher).
That's all I can remember at the moment, as I haven't played B&W in months because I lost my CD. D: D: D: