im curious as to how, if at all, weapon switching in D2:LOD changed the game. seems to me kinda silly to not include it in d3
i know all the hardcore people will run multiple item/weapon sets...i generally ran with 1 set of gear - the best i could get
It wasn't a huge impact, but it did enable a few different things that are not trivial. The first was weapon switching to an MF gear set right before killing a boss to get better drops. Depending on how much other MF you were wearing, this could be a non-trivial amount (~250 MF) if you had the best possible gear. The second was using a CTA to buff your skills and health, which could make several characters quit a bit stronger.
It's hard to say how much of an issue either would be in Diablo 3, though. We don't know much about how end game magic find will work, but I can see Blizzard wanting to remove the ability to easily game the system to get better drops. Their idea of balance is probably, if you want to have more MF, you'll need to wear it for the whole fight. I suppose players could manually change their gear, but I suspect that Blizzard would stop that if they felt it were causing issues. Also, given that we don't know anything about end game gear, it's hard to say if there's anything like the CTA in Diablo 3, although it's probably safe to assume there isn't.
Probably the biggest issue would be swapping between very fast and very slow weapons when building and spending resources. Imagine two weapons, both with 500 DPS, one that hits 3 times per second, and one that hits once per second. The first weapon would do 166 damage on average, whereas the second would do 500. Every skill in the game has damage based off of a percentage of weapon damage and many resource generating abilities are tied to how quickly you can attack as the amount gained is a flat amount per attack. The faster weapon would allow a Barbarian to cleave faster to build rage more quickly. Then he could switch to the slower weapon to cause more damage when spending the rage on skills like Hammer of the Ancients. Generally this would increase the damage that most characters could deal.
This leads to a potential problem with game balance. Do you balance the game around the assumption that players won't use the weapon switch technique or that assumption that players will use it? If you do the first, people will complain that the game is too easy. If you choose the second, it will make the game too difficult for some people who are unable to constantly manage their weapon choice in addition to the skills they're using.