"MP5 - This stat will be removed from the game completely. Holy paladins and Restoration shaman will be redesigned to benefit from Spirit." I'm guessing that means entirely gone from anything except your character read out. And to go along with the next part...
I had the same thought concerning the 5sr. It would seem reasonable/natural to me if Spirit gave 100% regen all the time and 50% in combat, without talents or anything. It would also fit the bill for being more intuitive (rather than the present system of regeneration), which is something they've stressed repeatedly with their stat changes.
An argument I was involved with quite a bit during the WotLK Beta was how Meditation fit into the scheme of things, and whether it was a really meaningless talent since every Priest spec took it. I'm not going to derail, but the best argument against Meditation was more directed at Spirit: Spirit is an undesirable stat for all classes unless propped up by talents/abilities. Stats like Agility, Str, Stam are naturally useful to their respective class/roles; Spirit and Intellect have been made useful by other means. We've already seen the Int/Sp change, so it would make sense to me if Spirit stopped requiring as many talents to make it a desirable regenerative stat.
Edit: What I'm curious about is the future of Replenishment. They've already hinted that it's probably not going to remain the way it is now, since Int will be desirable without needing Replen/talents to justify it. It would seem likely they'd perhaps involve it with spirit, but seeing as only 2-5 members of the raid will need it...who knows.