i have used vdmx since version 2. absolutely amazing software! everything midi-controllable, there even used to be a cool font-synth too.. excellent for live performance and/or producing clips on the fly.
recentely i focused more on music making than video mixing so i lost i little bit of experimenting with the latest release v5.
grab the beta here:
http://www.vidvox.com/
enjoy!
more infos and different apps, techniques, forums:
http://www.vjcentral.com/