Player trading is a key aspect of many MMOs and given Destiny's focus on social activities and playing in groups, it seems bizarre not to include the feature at launch. Then again, Destiny encourages players to grind for items and upgrades; player trading undermines that core gameplay value somewhat. Plus, with Exotic weapons and gear becoming increasingly common, is there really a need for player to player trading? The answer is yes, to some extent. Many valuable items in Destiny - like Ascendant Materials and Strange Coins - can only be obtained in limited amounts; players looking for one specific upgrade material might like the option of bartering with their friends for a trade. Bungie's current system prevents players from upgrading too fast and growing bored of the game quickly but right now, with the developers eagerly trying to push players into raid content, it's a little unbalanced. Players needing Ascendant Shards to upgrade their gear will only find Ascendant Energy and so on - it would be nice to be able to cut a deal with other players. Somewhere down the line (perhaps when the game has a currency that is actually worth something), player trading will undoubtedly be implemented. In some form though, it's a sought after feature right now - offering an alternative to grinding and raiding is a must for solo players.
I have an addiction to achievements, a craving for new bands and a dream to become Captain America. I once finished second in a Mario Kart 7 tournament so I'm kind of a big deal.