If you wanna read em:
Paquay, François S., et al. “Absence of Geochemical Evidence for an Impact Event at the Bølling-Allerød/Younger Dryas Transition.” Proceedings of the National Academy of Sciences of the United States of America, vol. 106, no. 51, 2009, pp. 21505–10
Surovell, Todd A., et al. “An Independent Evaluation of the Younger Dryas Extraterrestrial Impact Hypothesis.” Proceedings of the National Academy of Sciences of the United States of America, vol. 106, no. 43, 2009, pp. 18155–58.
Update: Found (some?) ice core evidence, it is indeed more recent, but I'm hopelessly out of my wheelhouse at this point so I'll just cite it for anyone also interested and suggest that these more recent publications do seem pretty confident in their conclusion that the impact did happen. So it seems user moloch-hai is correct:
Petaev, Michail I., et al. “Large Pt Anomaly in the Greenland Ice Core Points to a Cataclysm at the Onset of Younger Dryas.” Proceedings of the National Academy of Sciences of the United States of America, vol. 110, no. 32, 2013, pp. 12917–20.
Pretty cool stuff, thanks for sharing and prompting me to learn more about it.