I did indeed notice they upped the drop rate on some of the "old world" gather quests, which was sure nice, let me tell you! The difference between original zone gather quests, and those in Outland/Northrend was like night and day, sometimes, before 4.03a.
Just to give an example, there is one quest in Dun Morogh, carried over to Cata, where you have to collect some boar ribs and malt. The drop rate on those ribs used to be crazy low....I'd just do a bunch of other quests, and eventually I'd get the ribs, along with pelts and other things. Now, though, it was four boar kills and four rib drops. Also, even with drop rates on (most) quests being quite high, leveling is so fast that you really can pick and choose areas you want to quest in. No more having to go this zone and that zone to do a few quests, which is nice because when I level my worgen, I can go to all the zones I missed on my priest, and probably end up skipping most of the places I quested with him.