Many speakers at the Dev Summit blogged their slides and source files. Here are some links I could grab by following them on twitter :)
Adobe Flash Catalyst – The user experience design of tomorrow, today by Harish Sivaramakrishnan
http://blog.flexgeek.in/2009/12/devsummit09slides/
Data centric development on Adobe Flash Platform by Sujit Reddy G
http://sujitreddyg.wordpress.com/2009/12/03/slides-and-source-files-from-data-centric-development-session-at-devsummit/
Custom Components in Flex 4 by Mrinal Wadhwa
http://weblog.mrinalwadhwa.com/2009/12/01/custom-components-in-flex-4/
Introduction to Flex 4 Skinning architecture and Debugging: Tips and Tricks by Saurabh Narula
http://saurabhnarula.com/blog/presentations-on-skinning-in-flex-4-flex-debugging-tips-and-tricks
Flex and ColdFusion by Yash Mody
http://www.teknopoint.info/CF_N_Flex.ppt
Will post if I can find more.