Save your BoJ. With 2.4 come
some amazing items.
While the information and rumors from 2.4 start to become more firm, the smart money is to play very conservatively. Save your Arena, Honor, and BoJ and you might be in a great position to jump on some very sweet items soon after release. Spend yourself down and that's just more time it'll take to collect those things again while you and your Guilds will be focused on learning the new content.
But if you're dead set on spending the BoJ you have now, the better item will definitely depend on your current gear and Talent spec. It's most likely that the haste piece won't be better than the other, unless you've got a decent amount of HR from other items. But no one can say one is better than the other in a vacuum.