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Since its inception, the Copenhagen interpretation of Quantum Mechanics has been used to justify mysterianism, subjectivism, postmodernism, relativism, the preferred status of consciousness and human beings in the universe, a realm of intuition outside of logic and science, and other intellectual errors too many to number. It seems that people who reject reason and science grasp at every straw.

Good that experiments are now bringing this interpretation down. Nature has a feature on this paper (arXiv:0806.3547; Katz, Neeley Et Al. 2008).
The paper abstract:

We demonstrate in a superconducting qubit the conditional recovery (”uncollapsing”) of a quantum state after a partial-collapse measurement. A weak measurement extracts information and results in a non-unitary transformation of the qubit state. However, by adding a rotation and a second partial measurement with the same strength, we erase the extracted information, effectively canceling the effect of both measurements. The fidelity of the state recovery is measured using quantum process tomography and found to be above 70% for partial-collapse strength less than 0.6.

Nature comments:

To physicists raised on the textbook Copenhagen interpretation, any notion of uncollapsing a quantum state seems “astonishing”, says Markus Büttiker, a quantum physicist at the University of Geneva in Switzerland. “On opening the box, Schrödinger’s cat is either dead or alive — there is no in between.”

However, a more recent interpretation of quantum mechanics, ‘decoherence theory’, suggests that collapse does not occur instantaneously. Instead it plays out gradually as the quantum system slowly interacts with its environment (see Nature 453, 22–25; 2008). In 2006, Alexander Korotkov of the University of California, Riverside, and Andrew Jordan, of the University of Rochester in New York, proposed that this may leave open a time period in which experimenters could intervene to halt the collapse (A. N. Korotkov & A. N. Jordan Phys. Rev. Lett. 97, 166805; 2006). They provided blueprints for an experiment to test the idea, which Katz, Korotkov and their colleagues have now done.

It should be noted that decoherence by itself does not say how we should interpret the Quantum Formalism.

To quote from Wikipedia:

Decoherence is not actual wave function collapse. It only gives the appearance of wavefunction collapse. The quantum nature of the system is simply “leaked” into the environment. A total superposition of the wavefunction still occurs, but it exists beyond the realm of measurement.

Where does this new experiment leave us? Hard to say. A nice website with many references for further research is www.decoherence.de.

I myself, while tending strongly towards MWI (full ontological commitment to other “branches”) am not yet decided, simply because I haven’t looked at other interpretations enough - Bohm (a theory which does not sit well metaphysically with me though) or Relational Quantum Mechanics or Consistent Histories (which are similar to MWI but differ in details); I think we will simply need more experimental evidence to decide, evidence that will arrive as the quantum world is starting to get harnessed.

And, although the quantum formalism underlying the “interpretations” is the same (and thus the calculations come out right everywhere) the metaphysical assumptions and commitments one has to make are quite different - and these can be bolstered or corroded by experiment (using plausible reasoning).

The mess we’re currently in is nicely depicted here (Wikipedia).

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