Personally, I think those detectors are very likely to be a waste of time. We're just building what are basically better neutrino detectors, not because there's any reason to think dark matter will interact with them, but because it's a detector we know how to build!
I guess partly it's a case of whether dark matter is "massive particles that interact via the weak force" or "massive particles that interact weakly" (via some other force) - if it's the latter, these detectors aren't likely to work.
There are lots of theories about what the "WIMPs" really are - there's no evidence of weak force interaction, it only sets an upper limit on their interaction cross-section. Heck, even that's only true if dark matter was found in equal amounts of matter and anti-matter in the early universe, which is a heck of an assumption since we don't understand why familiar matter had such a matter/anti-matter imbalance early on. If dark matter had the same imbalance, then far more possibilities open up, as long as it doesn't interact with light (or I guess the strong force, as these detectors should really have worked in that case).