I think he's fine the way he is. Taunt is very useful, just use it before they break the snare from Powerball.

I find him a bit too squishy for a tank.. I think his HP needs a tad boost. Otherwise, I like him. Not quite as good as Singed / Amumu / Sion / Nunu.. but he is pretty good.

Love Rammus, one of my favorite heroes in the game. No problems with him.

He used to be awesome but then they nerfed all his abilities and his hp in one patch... (ok, maybe they didn't nerf taunt that patch--don't remember) poor guy has seemed a bit weak since but is still capable. I think the loss of the hp and ult nerfs hurt the most. It feels like you need to pick up 2 doran's shields (or something similar) to be a real tank in the early game.

However, the new hp, armor, and gold item seems perfect for him so I need check him out this patch.

He's fine tanks strong and can absolutely control a fight with his spin and taunt. Try rolling into players and than using his taunt at point blank if you're having problems with the range on his taunt.