Security Mobile and RFID by Nick von Dadelszen at KiwiCon. Interesting talk on RFID attacks using the Nexus S. This does not cover NFC but is a good read. Unfortunately not many details in the slides.
Axelle Apvrille did some nice work on how to utilize OpenBTS for mobile malware analysis. Both, paper and slides, make a nice read.
Ruxcon is already on, I found one possibly interesting talk Mobile and Contactless Payment Security by Peter Fillmore. But since the con is not done yet slides are not available at the time.
SyScan Taipei has a bunch of mobile stuff. Charlie Miller on iOS code signing. Stefan Esser on iOS kernel exploitation. I'm waiting for slides as the con is just over today.
New Academic Workshop MoST on Mobile Security Technologies at IEEE S&P in May 2012.