You can easily export from Blender your files in The Quicktime PNG
format or Quicktime Animation format, that way your alpha channels
are preserved and when you drop them on the Vegas timeline you change
the Alpha Channel to Premultiplied.
Steve Rhoden (Cow Leader)
Film Maker & VFX Artist.
Owner of Filmex Creative Media.
Samples of my Work and Company can be seen here:
https://www.facebook.com/FilmexCreativeMedia