I think the fact that Hal's costume has changed so little over the years goes to show how well it was designed to begin with. It's sleek, simple and effective, and the few changes they've made (green shoulders, black "pants" instead of green at the crotch) have all been improvements, but they were just tweaks, not wholesale revisions.
I also appreciate the fact that though big chunks of Hal's history with Green Arrow and with Alan Scott no longer apply in the New 52 that most of his history can still work.