One thing that has been a major issue in quite a few guilds I have been in is cloth on a balance druid and it usually comes down to the same argument every time: druids can wear cloth AND leather, but clothies only cloth so they should get dibsies right? Well its not that simple and anyone that thinks that it is that black and white is very narrow minded.
Lets look at it from both sides point of view. clothie: can only choose from cloth items even though cloth is the most plentiful and usually best itemized as far as non-tier items go so they don't lose anything, but don't gain anything either. Leather/mail users: have the ability to wear both their armour type and cloth(or leather for mail users), but both are usually itemized more heavily with spirit or mp5 which is even worse. Not to mention the amount of those is a lot less, but still they do have additional options and when they do have more options i believe they should pass to clothies
Now where it starts to get very muddled and more subjective is when your talking about BIS items that are cloth. Say I'm a balance druid wearing a 264 piece of cloth or leather in a random slot, then a 277 cloth piece drops, its bis for every single caster in the raid, and this is where you need to re-evaluate the options idea, if the only upgrade you can get is cloth then how does a druid have any more options then a clothie? But a lot of clothies just assume that since leather can be put on your character sheet that that means you magically have "different" BIS items. There is only one BIS item, if there is a leather equivalent or something reasonably close then still its just common courtousy to pass, but i feel druids are punished because people misunderstand what the term option actually means and the idea of telling the druid to not upgrade an item is more then unfair.
so to put it simply so that most ppl can understand it. what makes a clothie a clothie is the fact that the only upgrade he can get is cloth, so if your a balance druid and you only feasible upgrade is a piece of cloth you are literally on the same level and the clothie should be awarded no dibs at all, especially since blizz designed the game so that moonkins could wear cloth and come on clothies would just bitch if they ever made leather that was itemized better then cloth, so just be happy you always have access to BIS caster loot, but of coarse it seems with the idea of mastery and spirit/hit conversion this argument is going to be mostly if not entirely invalid come cata.