I think it's time to greatly increase the JP source when next patch hits. Overall, I love Mists of Pandaria, but I find it incredible wierd how VP is so much easier to farm than JP. In special for those who want to level alts and plan to buy heirlooms, to farm Honor and convert it to Justice Points is so much faster than to actually farm VP.
I know Ghostcrawler said they plan to convert the excess Valor into Justice once you hit the cap, but I think this is NOT enough. All bosses from Heroics should drop 70 JP each. The bosses on scenarios should also drop a handful of JP. Finally, those stupid gold bags we get from bosses when we win no loot should contain 45 JP each.