There seems to be some question over wether or not this can be done or not, there's a thread over on AV forums about it,
http://vjforums.com/showthread.php?t=27986&page=2
I think it's got to the stage where it's out of my hands now and it's down to either Pinky or Resolume to take some steps towards possibly developing something thats compatible between both apps to allow for vynil controled video/effects, or perhaps you guys have plans to implament tcv for control of video/effects peramiters yourselves I don't know.
I should think a great many people would like to use this feature if you could develop it? It would be great to see it implamented in a proffesional composition app like Resolume, as things stand now there are only limited "DJ" style apps (virtual DJ) etc which do not allow composition work.
Video scratching may not be to everybody's taste, it's cirtainly a bit hit or miss, but with the inclusion of effects manipulation to the bargin I think it could really open up a lot to artists. I just wonder what your thought's are, or if you have set any plans in motion yet? Personally I can already manipulate graphics and video well enough just using audio and midi hardware, but it would be another Avenue worth exploring imo.