Transports are still worth it. The main job is to add an extra layer of defense and mobility to your troops. Which they still do. They may have been nerfed, but they remain viable as always. Besides chimeras are the mainstay of imperial guard lists to begin with so you will stay fine. Your other common tanks didn't lose much either. Honestly nothing did, gw just made you rethink your investment into a transport/tank. Overall 6th edition will be the same for most armies and even make them better, the army rankings will not change at all.
