PSA: It is not OK to need roll on items for disenchanting without permission!
I've seen this a lot recently, and I know this is not likely something to get any attention by the offending party, but I figured I'd post this anyway, just in case someone is not clear on this.
When you need roll, this means you need the item to equip it for better stats for your current spec. Not the shard or dust or other material that comes from it when you disenchant it.
Unless your group gives you permission to do so, you should not need roll on anything you do not need to equip for your spec. This is bad manners, inconsiderate, and likely to get people to treat you the same way or worse.
Here's an example situation: You are a rogue/druid/warrior/hunter, and you convince yourself it is perfectly fine to take items from the rest of your group for your own enchanting needs, and then the item you've been farming for weeks drops, like a coveted ARP trinket. Then the mage need rolls on it because you've been taking all the items he wanted. Guess what, no trinket for you, because you were an ***, so you got treated like one. :)
So in closing, I know I'm probably going to get flamed for trying to teach manners and common courtesy on the internet, but to the people who do this kind of crap, STAHP IT.