cool!
Vampires. Cool. That is quite good so far, I think you should go into the plot in more detail. I advise you to add some sound effects, but the music was fitting (me=MuDvAyNe fan :-) and I liked your use of frame by frame (I love it and I always give good marks to people who use it) In the next part, you should go into detail on the main characters, and develop a plot, perhaps write out a script before you even start animating (that's what I do) and if you are artistic, you could make up some storyboards. So yep, guess that's about it, good start to a series, don't give up on flash, and keep pushing yourself to your limit, that's all I have to say. Hope this helps!
Adam