Adobe Flash is getting more and more popular as the platform to develop multi-touch applications on.
See also my post at http://www.multitouch.nl/?p=216 regarding a Summit that will be organized between Natural User Interface and Adobe in 2009 with the main focus on development of multi-touch solutions on Adobe's Flash platform.
In case you haven't seen my post on our NUI Group community website regarding that event, please have a look here: http://nuigroup.com/forums/viewthread/3582/
Because of the growth in interest for multi-touch software development on the Flash platform, we made a quick video as a proof of concept of Flash applications running on the tracker of NUI Suite Snowflake.