I don't understand the "too early to tell" thinking. To me, it's pretty easy to see that as of now the value of those picks - which of course incorporates the possibilities that they might be high or low picks, or steals/busts given draft position - easily outstrips what the Nets got in return, even considering unloading Wallace and the other assets going in both directions (e.g., getting out from under the Jason Terry disaster which is IMO an under-appreciated aspect of the trade).
Suppose you turn back the clock to July 2013, but everyone knows how washed up KG and Pierce would end up being this year. Would the Nets give up the same value, more, or less? I think the answer is pretty clearly "less." So, as of now we're the winners.
Things could change of course. Maybe the picks will stink. Maybe Pierce will be MVP next year. All kinds of crazy things could happen, who knows. But with the best information we have today, I think we are winners.