Hi, i just wondered if anyone here knows about Slomovideo - http://slowmovideo.granjow.net/
It is an opensource software that lets you slow down or accelerate video (image sequences too), recalculating the tweened frames. It gives really impressive results!
It also has some obscure math vodoo to create effective motion blur, handy especially if you are accelerating frames (or if you forgot to enable it in cycles ;))
I don’t know if the license permits it, but if some dev around here is willing to work on the NLE, this would be a worthy project IMO.
Remember the time when we didn’t have video tracking? Well, actually we miss something like this in Blender