I think trading us both a good idea and a bad idea. It is good cause of my friend has this sweet sniper rifle but hates being a sniper he could trade it to a friend for a shotgun he likes cause that is more his play style. However, on the other hand that hampers the feeling of being unique and having a gun that is truly yours and not a copy of someone else's. I think an auction house is a horrible idea. For a few reasons. 1. It cheapens the experience and the equipment you get. 2. Why should one person have to fight hard for a legendary but then someone can just walk up to a house and buy it. 3. It ruins the community overall. It didn't work with Diablo III at all and should be avoided.

We will have selling, buying, trading, and even gambling in Destiny. Now if this is with other gamers I am unsure of. if it is then to what extent will be very interesting. Personally I hope that items are BoE ( bind on equip) and save the best items like exotics to be BoP (bind on pickup). I really hope we will see an auction house since this makes it easier then trolling your friends for items XD.

Unknown what the extent of trading will be. My personal guess is that Exotics will be BoP, but that's just speculation on my part. Hopefully we get some clarification soon.