I'll add a few more to the burgeoning list...

Most recent report:
(Do Milky Way's Companions Spell Trouble for Dark Matter?)
http://www.ras.org.uk/news-and-press/21 ... ark-matter(The VPOS: a vast polar structure of satellite galaxies, globular clusters and streams around the Milky Way)
http://arxiv.org/abs/1204.5176(The Vast Polar Structure around the Milky Way )
http://www.youtube.com/watch?v=nUwxv-WGfHMFrom this press release:
"Our model appears to rule out the presence of dark matter in the universe, threatening a central pillar of current cosmological theory. We see this as the beginning of a paradigm shift, one that will ultimately lead us to a new understanding of the universe we inhabit."
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As Steve points out, there's also this recent paper related to the one above:
(The dark matter crisis: falsification of the current standard model of cosmology)
http://arxiv.org/abs/1204.2546"The current standard model of cosmology (SMoC) requires The Dual Dwarf Galaxy Theorem to be true ... The Dual Galaxy Theorem is falsified by observation and dynamically relevant cold or warm DM on galactic scales cannot exist. It is shown that the SMoC is incompatible with a large set of other extragalactic observations."
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Report from a week or so prior:
(Serious Blow to Dark Matter Theories? -- New study finds mysterious lack of dark matter in Sun’s neighbourhood)
http://www.eso.org/public/news/eso1217/(Kinematical and chemical vertical structure of the Galactic thick disk.
II. A lack of dark matter in the solar neighborhood)
http://arxiv.org/abs/1204.3924http://www.eso.org/public/archives/rele ... so1217.pdfFrom that week's press release:
“The amount of mass that we derive matches very well with what we see — stars, dust and gas — in the region around the Sun,” says team leader Christian Moni Bidin (Departamento de Astronomía, Universidad de Concepción, Chile). “But this leaves no room for the extra material — dark matter — that we were expecting. Our calculations show that it should have shown up very clearly in our measurements. But it was just not there!”
“Despite the new results, the Milky Way certainly rotates much faster than the visible matter alone can account for. So, if dark matter is not present where we expected it, a new solution for the missing mass problem must be found. Our results contradict the currently accepted models. The mystery of dark matter has just become even more mysterious."
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And then there's this from back in the day (2010):
(Dark matter claims thrown into doubt by new data)
http://www.newscientist.com/article/dn18839(First Dark Matter Results from the XENON100 Experiment)
http://prl.aps.org/abstract/PRL/v105/i13/e131302http://arxiv.org/abs/1005.0380Xenon 100 observations find no candidate DM detections, despite being more sensitive than DAMA & CDMS-II.
Though fellow researchers got their knickers in a twist about it...
(Dark matter 'no result' comes under fire)
http://physicsworld.com/cws/article/news/42554Sure, the Xenon 100 report was after only an initial 11 day run. But still, 0 detection candidates is 0 detection candidates.
And then about 90+ days later:
(Dark Matter Results from 100 Live Days of XENON100 Data)
http://arxiv.org/abs/1104.2549"In 100.9 live days of data, acquired between January and June 2010, no evidence for dark matter is found."
So, basically the same result in 100 days as in the 11-day trial run... No evidence of dark matter.
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All signs point to "Mister, when you're from Skid Row, ain't no such thing!"
(Bonus points if you know what movie that's from, without looking...

)
As far as I'm concerned, Dark Matter is seeming pretty well falsified.
Time to revisit Peratt's work on fully electrodynamic PIC simulations. Rotation curves of galaxies come naturally therefrom, no CDM required. Newer, bigger, better simulations required. I'd love to see them re-run with greater spatial and temporal resolution... Still, very suggestive. And that was back in the mid-80's. The Standard Model has a few decades of playing catch-up to do...
http://plasmauniverse.info/papers.html(Evolution of the Plasma Universe: I. Double Radio Galaxies, Quasars, and Extragalactic Jets)
http://plasmauniverse.info/downloadsCos ... 6TPS-I.pdf(Evolution of the Plasma Universe: II. The Formation of Systems of Galaxies)
http://plasmauniverse.info/downloadsCos ... TPS-II.pdfJust my 2c worth...
Best,
~Michael Gmirkin