If you've been following the Nature articles on stress induced stem cells (Odeck and main page posts here, here, here, and here), you'll know that the studies are under investigation by the RIKEN institute, where the investigators performed their experiments.
Today, they've released an interim report releasing their findings so far. In short, they have addressed 2 of the 6 suspicious items within the paper, and have found no evidence of scientific misconduct.
I. Items on which conclusions have been reached
(1) Obokata, et al, Nature 505:641-647 (2014) Article (Paper 1) "Unnatural appearance of colored cell parts shown by arrows in d2 and d3 images of Figure 1f"
It was concluded that the process of preparing these images did not constitute fabrication within the context of research misconduct.
(2) Obokata, et al, Nature 505: 676-680 (2014) Letter "Strong resemblance between the rightmost panel in Figure 1b and the lower panel in Figure 2g, both showing a fluorescence image of mice placenta"
There is no reference to the figures in either the figure legends or the main body of text, and this discrepancy is within the context of fabrication as defined by RIKEN's regulations on research misconduct, but there was nothing to contradict the explanation that one of the figures had inadvertently been left undeleted during the process of manuscript creation. It was therefore concluded that there was no malice intended, and this was not judged as a case of research misconduct.
They also mention that they intend to determine whether it is possible to reproduce the STAP cells, which hopefully means they have independent labs investigating the protocols. In the end, what is most important is that we get the science right, and we glean whatever information we can from these studies. It'd be great if there was some truth to the method, and the proper protocol can be released to the scientific community. Otherwise, people can stop wasting their time trying to reproduce these results, and move on with doing all sorts of amazing things with stem cells.
ETA: I'm noticing a lot of traffic for this (guys...where are you coming from?!), so just want to stress that this is an investigation in process, and there are still 4 more items to be investigated. It could very well be that misconduct could be found with any of those items, and its up to the investigators to parse it out. I would not be surprised if the papers are retracted, and I just hope that this does not cause too much of a stumbling block to the field.