This rises a question in me: What did we do for Chernobyl? It was decades ago, so most of this technology didn't exists yet. Or it was not nearly as bad as Fukushima?
According to the article, for political reasons, Japan wants to dismantle Fukushima, instead of simply neutralizing it, covering it up with concrete, and walling it off for a few decades before the cleanup happens. This is where the challenge comes from.
Unfortunately, I no longer have access to the journal subscriptions, so I don't have the full text of this, but I think this is the paper you want to read for an overview: http://onlinelibrary.wiley.com/doi/10.1029/96WR03963/abstrac...
The conditions are very different at Fukushima, mainly due to the proximity to the ocean, so I can't really give an educated summary of the challenges with that. One thing that you have to keep in mind, though, is that water is an excellent radiation absorber, and it's actually safe to go diving in active reactor pools as long as you're more than a couple of meters away from the core. I'd expect that the radiation in the ocean would disperse quickly and harmlessly.
The accident itself was worse and spread more radioactive material (the core exploded, the graphite ignited and spread a huge plume of smoke). But the cleanup effort if Fukushima will probably be worse because they are dealing with three reactors that still need cooling, leaking water etc.
As much I remember, in Chernobyl the core stopped before it reached the ground water, because they digged below the core and made it stop -- risking and probably sacrificing further lives.
Decades from now the cores will have been safely removed from the Fukushima reactors, the reactor vessels cut up and all of it will be safely stored in a nuclear waste dump.
Chernobyl won't be in noticeably better shape than it is today. It will still be a concrete lid over a still-active meltdown.