CDN has nothing to do with "reg flash" or any other "type" of content.
You can just as easily put "regular flash" (I assume you mean something akin to youtube?) files on CDN. If you mean streaming, you can as well - many CDN services support streaming.
Basically, CDN on average should increase throughput substantially, vs. single-point hosting. The technology your site uses to push the video should be irrelevant, it will still be faster (on average) on CDN than it would be via a single location. Basically, it's simple physics due to the speed of light
-Phil