Since this seems to be a time where we dig out the little things that we have discovered as suboptimal or little errors, I have this little thing that used to annoy me, but now I have just gotten used to the way vvvv does not detect the pixel aspect of video.
It would be pretty practical if either the VideoTexture nodes or FileStream could output the pixel aspect so that it would be possible to handle video content with mixed pixel aspect ratios automagically.
An example would be a situation where you in a live setting are getting video from different sources with cameras in different formats: 4:3 and 16:9 probably PAL. In this case it would be pretty handy to be able to just throw the captured clips straight into vvvv regardles where it came from.
As often before I have no clue if this would be difficult to implement or not, quicktime for one cannot do it by itself (At least, I have only found out a very complex way to set it manually)