Well, I also brought my first video to the web the week before christmas. As far as I found out, the ability to insert metadata depends on the player you use.
I did NOT submit my video to youtube, because it was my first one. Will do so later on with some selected videos, but I want the majority of my material to be available solely on my own website. (Which - so my speculation - is a positive ranking factor, btw!)
It could also be the case that adobe's professional software offers means to insert such metadata right into the flv-file; but I cannot tell about this. The freely available conversion-tools, which I found and used, do not.
Flash is a traditionally "weird" research field for SEOs, eh? Too much to learn about it still, few information over the web, but a great chance just because of this...