Add to the list of items broken by BC the art of fishing.
You see, fishing skill-ups follow an exponential curve. The closer you get to 300, the more catches you need to make to gain a skill point. It isn't tied to difficulty at all (unlike all other professions).
Well, the geniuses at Blizzard didn't change the algorithm when they changed the top end to 375. We all know what happens when you extrapolate a exponential curve, don't we kiddies? I don't know where the asymptote is, but I can tell you that getting anything over 300 is painful (I fished for maybe an hour total and am at 305...compare that with 375 first aid and 320-360 in everything else).
Didn't they play test this?
Oh, to add to the discussion about Z-marsh. There are areas where 350 skill isn't enough to fish (north shore of Coilfang Reservoir, for example). Bumping it to 425 still results in fish getting away. So for skill ups, I'm going to stick to the east end of the marsh.
I saw someone fishing in the goop in Hellfire. Dunno what they were catching (wouldn't talk), but their bobber would work. Didn't try it myself.