1) Please don’t spam nourish without HOTs for either raid healing or tank healing. Please. See my healing guide for more info. It’s just bad, Mkay? Your primary heals are still HOTs. Nourish is now just a better tool to help in appropriate places…
2) Spirit is still valuable for raiding tree druids, even though it’s not as good as it used to be. The effect of spirit only changed for: While you are NOT casting, and for innervate.
So, if you spend most of your time casting, then the value of spirit hasn’t drastically changed for you. While some people are recommending abandoning spirit altogether for healing in favor of mana/5, I think that’s way too extreme of a viewpoint. If something with mana/5 on it looks appealing to you as an upgrade from what you are wearing, then pick it up. I have a couple pieces in my healing set that has mana/5 without spirit, and having a couple pieces without spirit on it won’t hurt. However, if you totally avoid spirit on every piece of gear, your innervate is going to return no mana to you and that will make you very sad. Moonkin need less spirit than resto druids because spell crits give moonkin back mana. Resto druids still need the spirit that is on your gear, because it gives you increased healing as well as mana regen and a more powerful innervate effect. You would only want to stack mana/5 without any spirit if you plan to stand around not casting for long periods of time during a fight… in which case, mana probably isn’t a problem in the first place… Having some of both is fine.
There may be cases for PvP where mana/5 becomes really helpful above the value of spirit. However, in Ulduar raid healing, you won’t spend enough time out of the 5 second rule for it to matter in the vast majority of fights.