Not that I'm necessarily against trading picks, but one argument to keep the current ban:
There is a lot of concern going around on new GM's coming in and destroying a team then quitting, leaving future GM's with little or nothing to work from. Preventing the trading of picks ensures that a new GM will have at least a full slate of picks to work from in the upcoming draft. Along the same lines, if we rolled back the current rule and went back to allowing picks to be traded, I think we should definitely continue to disallow trading of future picks (even more important for future picks).