Rammus is weak currently, and doesn't fit in the meta. In fact, most true tanks don't fit in the meta anymore. This was the case before the season 3 changes, and probably won't get reversed.
Top is for bruisers, jungle is for utility, and support is for support. True tanks need items to tank and disrupt the enemy, but they have a hard time farming/laning/generating gold. Obviously there are exceptions (malph top, ali/leona support) who's kit allows them a huge tanking advantage without items.
But apparently tanking is "anti-fun" while being a bruiser isn't. I guess Riot sees the carries as the "fun" roles, and being unable to kill stuff isn't fun. So then why does anybody play support? why is there even a support class? Why are there tanks if they don't fit in the meta? People enjoy disrupting the enemy, protecting the ADC, or supporting the team as a whole, and more attention needs to be payed to these roles rather than just the carries. Its class discrimination is what it is.
Instead of constantly releasing new champions, there should be a turn towards making current champions and classes, that people know and love, more viable. This includes tanks and supports. Riot has said they are trying to make supports more fun and easy to play, which is good, and they have released some awesome items and masteries for supports, but tanks are getting no recognition.
With over 100 champions currently in the game, its hard enough for new players to figure out what they all do and how to play against them. While its nice to have new champions all the time, it is frustrating to see current ones being neglected and outclassed by the new champs.
Bruisers even shut down tanks with items like the revamped black cleaver, theres almost no reason to play a tank or build defenses when the stats disappear in battle. the message I see is "Buy more damage. win.". No strategy or counterplay there.
All we can do is send Riot the message "We want effective tanks, tanking is fun", and hopefully, with enough people, they'll get the message and find a way to make tanks a viable role in the meta.