Well, now that we have the numbers and shit... besides Nautilus' package.
Wow, Sona nerf is huge. The aura nerf amounts to very little but the Power Chord hit is a massive loss to her early-game poke, she loses a good 30% damage on the first couple she's liable to hit enemy champions with. :/ That said, it was probably necessary to bring her in line with the other traditional supports. She'll still be the best laner, Janna and Soraka have no damage and Taric/Alistar are still melee, but she'll no longer be utterly dominant in this regard or be able to trade favorably with the enemy carry 1-on-1. Her late-game is untouched, her auras being a boon most champions can't compare with sans farm, not to mention her ult.
Soraka support looks dead, though. Feeding her carry mana doesn't nearly cover for her lack of personal damage output relative to Taric, Alistar or Sona and buffing that aspect won't change this. All of them can heal health, two of those three already more sustainable long-term than Soraka, and Soraka is otherwise the only support without hard CC. (Though one could argue that Infuse is a bit more generally applicable than Crescendo, Sona's CC is undoubtedly more powerful post-laning.) The only reason to pick her to begin with is the self-mana sustain, giving her much greater freedom in runes/masteries/item build than her counterparts. With that destroyed, I see no reason left to pick her. AP Soraka is mostly untouched if you like playing around with that at least. Infuse is free, so it's not like you spend much mana while laning anyway.
Alistar buff is cool, his combo is very mana-intensive in the laning phase. Another likely insignificantly but nonetheless unnecessary Ahri nerf and GP gets hit for about the 80th consecutive time. Fuck Cass and Kennen but they need tougher nerfs than those slaps on the wrist... same with Ryze.
Rammus DBC nerf looks pretty harsh to me, 30 Armor/MR is a lot. And I'm not sure why Riot hates casters but man fuck the Revolver nerf.
Oh, and jungle Shen is still going to be ass because his clear speed is still balls. Stick to top lane yo. 8) Warwick getting a surprise buff might change his fortunes, however. I think the base AS increase is rather large and will do more than the change to his passive but I suppose it doesn't matter either way. His clear time might actually be competitive again.