I think we're still a long ways from comparing this situation to Chernobyl. The release of radioactivity so far may make it more comparable to Three Mile Island as far as its actual impact on the surrounding area. And the containment vessel that actually houses the core still seems to be intact. At Chernobyl, you had the graphite core completely exposed to the outside, burning out of control and so hot that no amount of water could put it out, spewing massive quantities of radioactive fallout into the atmosphere.

At Fukushima, the control rods are all in place from what I understand, so the core will not go into uncontrolled fission. It's still generating heat, though, and that needs to be cooled or eventually bad things happen, but that's a far cry from the runaway disaster that was Chernobyl.